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Automatic Dishwashers

times, however, when the dishwasher is blamed for poor performance. Perhaps

the customer does not know how to load the dishwasher properly or the wrong

amount of detergent was used—in some cases, the dishwasher might not run at all. Whatever

the case might be, it is up to the technician to either repair the dishwasher or instruct the

owner in its proper usage.

This chapter provides the technician with the basic skills needed to diagnose and repair

automatic dishwashers. The actual construction and features might vary, depending on

what brand and model you are servicing.

Principles of Operation

After placing the dishes properly in the dishwasher, the detergent is placed in the dispenser,

and the rinse conditioner is checked for the proper level. The door is closed, and the type of

wash cycle is selected. The door latch holds the door closed and activates the door latch

switch. This will complete the electrical circuit for the dishwasher to operate. If the door is

opened during the cycle, this will cause all operations to cease.

The timer will energize the water inlet valve, and water will begin to enter the tub. The

dishwasher does not fill with water like a washing machine. It is designed so that the tub

does not have more than two gallons of water in it at any one time. Should the timer switch

contacts fail to open during the fill cycle, a float switch assembly, located inside the tub, will

open the electrical circuit to the water inlet valve at a preset level.

The fill safety switch is part of the float assembly. Should the timer fail to open its switch

contacts, water will keep entering the tub until the float, located inside the tub, rises and

a mechanical failure of the water inlet valve.

During the wash and rinse portion of a cycle, the heater element heats the water (on

some models) to at least 140 degrees Fahrenheit. This feature is built into the dishwasher

and is designed to save the customer money on the operating cost. Also, the customer does

not have to raise the water temperature of the water heater to 140 degrees Fahrenheit. He or

she only needs to set the water heater temperature at 120 degrees Fahrenheit. This will

prevent any member of the household from getting burned.

341

CHAPTER

The water is repeatedly pumped through the lower and upper spray arms and onto the

dishes (Figure 14-1). As the water runs off the dishes and back to the pump, it flows through

a filtering system. On some models, the filter is designed to separate most food particles

from the water so that they aren’t sprayed back onto the dishes (Figure 14-2).

At the end of a wash or rinse cycle, the water is pumped out of the dishwasher, flushing

the filter of any small food particles. The larger pieces of food are trapped on the pump

Front view of

dishwasher with

water circulating

in wash cycle

Side view of

dishwasher with

water circulating

in wash cycle

FIGURE 14-1

An outside view of

inside a dishwasher

tub with the water

circulating.

PART VI

guard, which must be cleaned out before the next use. On some models, the pump screen

removes food particles from the water, stores them, and then grinds them up as they are

washed down the drain. During grinding, some sounds will be heard. All dishwasher

models have some type of mechanism to dispense a rinse aid agent during the designated

rinse cycle. The rinse aid agent will not allow the water to stay on the dishes. This will

improve the drying time and prevent spotting and filming on the dishes.

At the end of the cycle, the heater element (Figure 14-3a) comes on (if selected) and helps

dry the dishes. Certain models have a fan that circulates the air to speed up the drying cycle,

Screw

Foreign object plate

Inlet protector

Chopper assembly

Sump

Pressure switch

Drain loop

(check value

molded inside)

Screw (4)

Accumulator cover

Accumulator

bottom

Filter assembly

Motor sheld

Screw

Motor subassembly

Shield-capacitor

Capacitor

Motor

Nut

Volute back

Face seal

Seal

Face seal-head carbon

Sump seal

joint

Impeller-weld assembly

Drain pump

Sump check valve

Separation screen

Silverware

basket

Detergent and rinse

conditioner dispensers

Upper

dishrack

Lower

dishrack

Lower spray

arm and

motor/pump

assembly

Heater Overfill

protector

Vent

Dishwasher

component locations.

thus making sure that the dishes dry evenly. Some models have a cool-dry cycle. This allows

the dishes to be dried without the heater element operating. Combined with the heated air

within the tub (from the wash cycle) and the dishwasher door opened a little bit, it will cause

the water that remains on the dishes to condense and roll off them. Figure 14-3a and b

illustrates component locations within the automatic dishwasher (under-the-counter,

portable, and dish drawer).

Safety First

install, maintain, or repair an automatic dishwasher. Any improper installation, preventive

maintenance, or repairs could create a risk of personal injury or property damage.

PART VI

If you do not fully understand the installation, the preventive maintenance, or the repair

procedures in this chapter, or if you doubt your ability to successfully complete the task on

the automatic dishwasher, call your service manager.

Before continuing, take a moment to refresh your memory on the safety procedures in

Chapter 2.

Dishwashers in General

Much of the troubleshooting information in this chapter covers the various types of

dishwashers in general, rather than specific models, in order to present a broad overview

of service techniques. The pictures and illustrations that are used in this chapter are for

demonstration purposes only—they clarify the description of how to service an appliance,

and they in no way reflect any particular brand’s reliability.

Timer and

controls

Door

latch

Door

springs

Pump and

motor

Water valve

Vent

Wheels

Dishwasher

component locations.

Dish rack

Spray arm

Control panel

Slide-out dish drawer

Double stack slide

out drawers

Dish drawer

dishwasher.

PART VI

Location and Installation of a Dishwasher

Locate the dishwasher where there is easy access to existing drain, water, and electrical lines

(Figure 14-4). Be sure to observe all local codes and ordinances for electrical and plumbing

connections. It is strongly recommended that all electrical and plumbing work be done by

qualified personnel. The best location for the dishwasher is on either side of the sink.

2" Access hole

Sink at right

Alternate drain through

floor into separate trap

Electric outlet

Electric

outlet

Sink at left

Remove knock-out

plug in disposer

Drain air gap

2" Access hole

Sink at right

Sink at left

Electric

outlet

Remove knock-out

plug in disposer

Electric

outlet

“Y” branch tailpiece

Entry must be

above trap

For proper operation and appearance of the dishwasher, the cabinet opening should be

square and have the dimensions as shown in Figure 14-5. If the dishwasher is to be installed

in a corner, there must be sufficient clearance to open the door (Figure 14-6).

Take the time to read over the installation instructions and the use and care manual that

comes with every new dishwasher. These booklets will provide you with very important

information, such as:

6"

6"

24"

20"

34¼" min.

7½"

2½"

1½"

90 90

Electrical, drain and

water supply lines

(entrances must be

confined to shaded

area)

Water or electrical

wiring on left

(depending on model)

Electrical wiring or

hot water line on right

(depending on model)

24 "minimum

Dishwasher

door

2" min.

Dishwasher Countertop

FIGURE 14-6

Corner dishwasher

installation

dimensions.

PART VI

Most important, read the warranty information that is supplied with the dishwasher.

Functions and Cycles

Dishwashers are similar to automatic clothes washers. They apply three kinds of energy on

the things to be washed. These forces are:

assembly to remove the food particles. Detergent is added to aid in cleaning of the

dishes.

and greases on dirty dishes. If the water temperature falls below 120 degrees

Fahrenheit, the customer must select the water heating option (if available).

the soils suspended in the water to be removed later in the cycle.

Rinse aids are added to the rinse cycle to prevent water spotting of the dishes and to

prevent the water from clinging to the dishes. A rinse aid agent will allow the dishes

to dry quicker.

Dishwashers perform four basic functions that are modified and put together in different

ways to create the various cycles. The four functions are:

As with clothes washers, the only difference between the wash and rinse cycles is the

presence of detergent in the wash water. The mechanical activities that make up a wash and

a rinse cycle are basically the same function.

Unlike clothes washers, most dishwashers fill and begin to wash (or rinse) at the same

time. The functions are put together in various ways to make up different cycles. For example:

the wash cycles and (on some models) also heats the rinse cycles. On certain

models, the timer will not advance until the water temperature is 140 degrees

Fahrenheit. This will extend the total time of operation. Depending on the model,

the cycle time can increase from 15 minutes to 2 hours. (Check the use and care

manual for exact details.)

Water Temperature

The temperature of the incoming water is critical to the operation of a dishwasher. Most

dishwashers have heaters, and some have delay periods that extend the time during which

water is heated to a specified point, but this does not fully compensate for low temperature

of the water supply. You can check the temperature of hot water at the sink nearest to the

dishwasher with a thermometer. Open the hot water faucet. Let the water run until it is as hot

as possible, and then insert the thermometer into the stream of water. On some models, if the

thermometer reading is below 140 degrees Fahrenheit, you will have to raise the water heater

thermostat setting. On other models, the dishwasher was designed to operate with water

temperatures as low as 120 degrees Fahrenheit. These models have longer detergent wash

periods that allow 120-degree Fahrenheit supply water to be heated up to a temperature that

gives good washability results. The dishwasher delay periods occur in only one, two, or three

of the water fills, and do little for the remaining rinses. Except during delay periods, the

water is not in the dishwasher long enough to be heated adequately.

Water Temperature Above 150 Degrees Fahrenheit

It is not recommended to have the water temperature above 150 degrees Fahrenheit in a

domestic dishwasher; above this temperature, certain components in the dishwasher might

be adversely affected.

Water Temperature of 150 Degrees Fahrenheit

A water temperature of 150 degrees Fahrenheit is the ideal temperature for a mechanical

dishwasher. Detergent action and the dissolving of grease are at the maximum at this

temperature. Drying of most materials in the dishwasher will be satisfactory.

Water Temperature of 140 Degrees Fahrenheit

Water temperature of 140 degrees Fahrenheit is the minimum temperature recommended

by most dishwasher and detergent manufacturers. At this temperature, detergent is still

quite active, and most fats are dissolved so that they can be emulsified in the water by the

detergent and washed down the drain. Drying will be fair to poor, as water temperature in

the last rinse is lowered toward 140 degrees Fahrenheit in some models. Some improvement

in drying is possible if a liquid wetting agent is added to the dispenser.

Water Temperature Between 130 and 140 Degrees Fahrenheit

Water temperature between 130 and 140 degrees Fahrenheit is outside the range for most

dishwasher operations, and users will have to exert special care if they are to obtain

satisfactory results. The cleaning action of detergents and the dissolving of fats are

gradually reduced as temperatures drop below 140 degrees Fahrenheit, so the dishes will

probably have to be rinsed well before putting them into the dishwasher. Satisfactory

drying becomes less likely as water temperature becomes lower. Some dishwashers have

an optional feature which will increase the temperature of the water in the tub at different

points during the cycle.

PART VI

Water Temperature Between 120 and 130 Degrees Fahrenheit

Water temperature between 120 and 130 degrees Fahrenheit will aggravate all of the conditions

and problems mentioned for the 130- to 140-degree range. Very few fats will dissolve, so the

greasy buildup in the lower areas of the tub will be accelerated. Sudsing and foaming are

more likely to increase. Detergent action is further reduced, so pre-rinsing of the dishes

becomes even more important. The water heat feature will most likely have to be used.

Water Temperature Below 120 Degrees Fahrenheit

Because of poor washing, grease buildup, poor drying, and foaming, it is unlikely that

the dishwasher will perform to the user’s satisfaction if the water supply is less than

120 degrees Fahrenheit.

The Detergent

The kind and amount of dishwasher detergent that is used is an important part of getting

the dishes clean. Different brands of dishwasher detergent contain different amounts of

phosphorous, which works to soften water and prevent water spots. If the water is hard,

you will have to instruct the customer to use a detergent with a higher phosphorous

content—above 12 percent. If the water is soft, the customer can use a low-phosphorous

dishwasher detergent. Some areas restrict the phosphate content to 8 percent or less. This

means that the customer will have to increase the amount of detergent used in those areas

where the water is hard. This is done by adding 1 teaspoon of dishwasher detergent

manually in the main wash cycle for each grain of water hardness above 12 grains (general

guideline: minimum of three teaspoons) (water hardness is measured in grains):

If the hardness of the water supply is unknown, contact the local water department.

If the user is using a concentrated detergent, then advise them to use half the amount

recommended earlier.

If the water is above 15 grains, the dishwasher will not perform properly (spots and film

will appear on dishes), and a water softener will have to be added to the dishwasher water

inlet supply.

Always instruct the user to use automatic dishwasher detergent only. The use of soap,

hand dishwashing detergent, or laundry detergent will produce excessive suds and will

cause flooding and damage to the dishwasher.

Loading the Dishwasher

To obtain the optimum cleaning performance from a dishwasher, the most important factor

is loading the dishwasher properly (Figure 14-7). When placed in the dishwasher, the dishes

should be positioned in relation to the wash action. The dirtiest side of the dishes should

face the source of the water spray. Glasses, cups, and bowls should be positioned slanted

and with the bottoms up to prevent any water from collecting on the bottoms. The flatware

should be loaded according to the manufacturer’s recommendations as stated in the use

and care guide. Any metal items that are loaded into the dishwasher should not touch one

another unless they are made from the same materials. Any contact from dissimilar metals

could result in permanent damage to the item. Do not place the silverware or dishes crowded

together; this will prevent the water from reaching all of the soiled items. Delicate items

should be positioned on the racks so they do not move around and cause breakage or

chipping. Remember, for optimum cleaning, never overload the dishwasher.

Types of Dishwasher Systems

The basic dishwasher cycles, regardless of manufacturer, will perform the same basic

functions when cleaning the dishes. One complete cycle consists of a water fill, water

circulation with detergent (wash cycle), then the water is pumped out (drain cycle), again

there is a water fill, water circulation without detergent (rinse cycle), and a drying cycle

(heated or air only).

Upper dishwasher rack

Lower dishwasher rack

FIGURE 14-7

Proper loading of the

dishes in the

dishwasher upper and

lower racks.

PART VI

Water Fill Cycle

All dishwashers have a timed water fill. The dishwasher timer (mechanical or electronic)

controls the amount of water that enters the dishwasher. In most cases, the customer’s water

pressure entering the home will dictate the quantity of water allowed in the dishwasher. If the

home has low water pressure, the dishwasher might encounter problems filling completely,

which will lead to not enough water to wash the dishes. Every dishwasher has an overfill

protection device called a float and switch to protect the dishwasher from overfilling. If the

water pressure is high, the float and switch will turn off the water inlet valve to prevent

flooding, regardless of how much fill time is left on the timer. Each dishwasher has a specific

time allotment for the amount of water needed for proper washing. The fill system for the

dishwasher will consist of the water inlet valve and the overfill protection device (Figure 14-8).

Water Circulation Systems

The wash phase begins after the water that entered the tub has reached the correct level.

This is the beginning of the wash cycle with detergent added. Next, the water pump

assembly begins to circulate the water and detergent (Figures 14-1 and 14-9). For a specific

period of time, the soil is removed from the dishes with water heated to 140 degrees

Fahrenheit and mixed with detergent. When the dishwasher stops and goes into the next

phase, the dirty dishwater is pumped out through the drain hose. Then the rinse phase

begins. This phase is the same as the wash phase but without the detergent. Some models

have two or three spray arms to spray water onto the dishes.

Float

Standpipe

Gasket

Micro switch

Standpipe nut

Power Shower

Tub Back

Telescoping Power

Tower

Wash Water

Self-Cleaning Filter

with Fine Mesh Screen

Pump

Back Flow

Valve Closed

Soil

Collection

Chamber

Filter

Check

Valve

Drain Line

Check Valve

To House Drain

Wash/Drain

Diverter Valve

Multi-Front

Wash Arm

Filtered Water

Return

Inlet

Motor/Pump Assemblies

After the water has stopped entering the dishwasher, the timer contacts close to begin the

wash/rinse cycle, and the motor and pump assembly will begin to run. The shaft of the

motor is connected directly to the pump assembly. There are many different types of motor

and pump assemblies manufactured (Figure 14-10). All of these motor and pump assemblies

accomplish the same thing. They circulate water throughout the tub, and most of them drain

the water out of the tub, too. Some models add a separate drain pump motor for draining the

water from the dishwasher tub.

PART VI

Overhead Spray

Coupling

Upper Spray Arm

Lower Spray Arm

Sump

Aqua Sensor

Flow Through

Heater

Feed Tube

Upper

Spray Arm

Middle Spray Arm

Water Inlet

Drain Tube

Accumulator

Check Valve

(in Drain Hose)

Heating

Element

Sump and Motor

Assembly

Float

Lower Spray Arm

Dispenser

Assembly

Door Latch Assembly

Electronic

Control Board

(Interconnect

Board Underneath)

Active

Vent

Inner Feed Tube

Control

Panel

Dishwasher Filtering Systems

Many dishwasher models incorporate some type of wash/rinse water filtering system to

separate the food particles from the wash/rinse water (Figure 14-11). This will prevent the

food particles from being deposited back on the dishes.

Dispensing Systems

Over the years manufacturers have developed many types of systems used to dispense

detergent and rinse agent into the tub (Figure 14-12). A dispensing system must be able to

dispense detergent in the wash cycle and also dispense the rinse agent in the rinse cycle.

Most dispensing systems used today are electrical or mechanical in nature.

PART VI

Top Spray

Upper Spray Arm

Lower Spray Arm

Module and Motor

Tuned absorber

Nut

Bearing

Seal

Water Tube

Spray Arms

Upper Impeller

Lower Impeller

FIGURE 14-9

Various types of water

distribution systems

used in dishwashers.

Drying Systems

Manufacturers also have used various systems for the drying phase. The drying phase

begins with the water fill. When a hot water supply is used in the washing phase, that will

assist in the drying process. When the dishes are heated by the hot water, they are better

able to evaporate the water during the dry cycle. Most dishwashers are equipped with an

electric heating element (Figure 14-13). Some models are also equipped with a blower motor

assembly to circulate the heat within the dishwasher during the heating cycle. Other models

use natural convection to direct the air flow in the drying process. Cool air enters the

dishwasher tub and is heated, and then the heated air rises and absorbs the moisture,

escaping through the vent in the dishwasher door. Various types of vent systems are used

(Figure 14-14).

Upper

Spray Arm

Lower

Spray Arm

Soil Removal

System

Pump

Third Level

Spray

Heating

Element

Normal Water

Fill Level

Motor

PART VI

Spray Arm Bolt

Spray Arm

Screw

Filter Body

Heater

Screw

Washer

Upper Impeller

Macerator Blade

Spacer Plate

Impeller Shroud

Pump Plate

Pump Gasket

O-Ring

Lower Impeller

Water Seal

Gasket

Screw

Housing

Clamp Ring

Water Shield Fan

Motor

Tolerance Ring

O-Ring

Diffuser

Screw

This is an older-model

dishwasher motor and

pump assembly

manufactured by

Frigidaire. This system

is a direct drive

system. In the wash/

rinse cycle, this type

of motor/pump

system turns

clockwise. In the drain

cycle, the motor/

pump system

reverses the direction

to drain out the water

from the tub.

Top Wash Arm Hose

Seal Washers

Outlet for Wash Arm

Upper Wash Arm

Nut for Wash Arm

Center Wash Nozzle

Lower Wash Arm

Lower Wash

Arm Gasket

Screws - Strainer to

Module (6 Used)

Strainer

Micro Mesh Filter

Bearing and Nut

for Wash Arm

Support for Wash Arm

Back Flush Arm

Power Module

and Components

Pulley for Pump

Mounting

Clips

Mounting

Bracket

Motor

Switch

Drive

Motor

Drive

Belt

Motor

Pulley

drive system, where the motor will operate a separate pump for wash and drain.

PART VI

Spray Arm

Support

Sump

Tub Bottom -

For Reference Only

Pump Connector

Connector Clamp

Support Nut

Mechanism

Hanger

Pump

Mounting

Screw

Complete Motor

Pump Mechanism

Pump

Housing

Clamp

Trap

Plug

Sump

Clamp

pump assembly manufactured by General Electric.

The motor is an induction motor with a capacitor. It is

quieter and more energy eficient.

dishwasher motor and pump assembly manufactured

by Whirlpool. This system is a direct drive system.

The motor turns in one direction for wash and turns

in the other direction for drain.

This dishwasher motor

and pump assembly is

an older model

manufactured by

General Electric. This

model uses a shaded

pole motor and only

turns in one direction.

To drain the water

from the tub, this

model uses a

solenoid coil to open

a valve to drain the

water.

To Upper Spray

Arm

To Lower Spray

Arm

Non-Return

Valve

Drain Pump

Cover

Drain Pump

Operating Capacitor

Circulation

Pump

Pressure

Switch

Thermostat 55/85°C

(NTC/85°C)

NTC

Aqua Sensor

assembly is a Whirlpool model. This model

uses a system for separating the food

particles from the recalculating water. It

will then lush the food particles down the

drain, keeping the water in the tub cleaner

during the wash cycle.

manufactured by Whirlpool. This dishwasher motor/

pump assembly is a direct drive system without a

separate pump-out motor.

It utilizes a direct drive system.

PART VI

closeness of the components, this model will have to

be removed from its installation housing to be

repaired.

Frigidaire. It uses a separate drain pump motor to

drain the water from the dishwasher tub.

Step-by-Step Troubleshooting by Symptom Diagnosis

In the course of servicing an appliance, you might overlook the simple things that could be

causing the problem. Step-by-step troubleshooting by symptom diagnosis is based upon

diagnosing the malfunctions, with possible causes arranged into categories relating to the

operation of the dishwasher. This section is intended only to serve as a checklist to aid in

diagnosing a problem. Look at the symptom that best describes the problem you are

experiencing with the dishwasher, and then proceed to correct the problem.

Before testing any electrical component for continuity, disconnect the electrical supply

to the appliance.

No Water to Dishwasher

1. Is the water turned on?

2. Is there voltage to the water inlet valve solenoid?

3. Is the water inlet valve solenoid defective? Disconnect the electrical supply, and

check the solenoid coil with an ohmmeter.

4. Is the water valve plunger stuck? Disassemble the water valve and check.

Soil Sensor

Fine Mesh

Nozzle

Lower Spray Arm

Seal Rings

Screw

Pump Cover

Tower Nut

Screw

Filter Base

Back Flush Arm

Filter

Support for Wash Arm

Upper Discharge Housing

Screw with “O” Ring

Recirculating Impeller

Lower Pump Cover

iltering system grinds up the food

particles before disposing the food

waste down the drain.

allows the food particles to be trapped by the iltering screen

before the water enters the recalculating pump.

PART VI

Cleaner water

escapes back

into the tube

through opening E.

A small portion,

approximately 5%,

enters tube B.

Is directed

to the upper

spray arm.

Most of the water

pumped by the

lower impeller.

Water lows

through the

separation chamber

lushing food particles.

Out through

drain port H

which is connected

to the drain hose.

To seal

opening E.

Lifts valve

F off

it’s seat.

Through tube G. Drain

The lower impeller

pumps water.

G

H

F D

B

E

Lifts valve D

off it’s seat.

E D

B

G C

F

And enters the

soil separation

chamber. Food

particles settle to

the bottom of the chamber.

Water will not

low from the

drain because

water pressure

is too low.

Drain

Start

Start

A

A

circulating through the pump as the food particles are separated from the wash/rinse water.

Food particles

separated from

water

Sump

Sump

Check

Valve

Auxiliary

Pump

Auxiliary

Pump

Main

Pump

Drain Solenoid

Collection

Chamber

Check

Valve

Check

Valve

Check

Valve

Collection

Chamber

model, the food particles are contained in a

separate chamber to be disposed of in the

drain cycle.

manufactured by General Electric will separate the

food particles during the wash/rinse cycle and

dispose of the food particles in the drain cycle.

auxiliary pump motor. This motor removes all remaining water

in the tub.

PART VI

Bimetal

a Maytag dishwasher. Current passing through the

bimetal will warp it, releasing the detergent.

It is the rotation of the timer and cam that moves the lever that releases the

detergent cup and rinse agent.

Conditioner dispenser valve

Solenoid

Wire harness

Nozzle

nut

Dipstick

Washer

solenoid to activate the detergent dispenser.

Rinse agent

dispenser

Detergent dispenser

Linkage to Dispenser

Draw Bar

Dual Wax

Motors

Wire

Connector

Wax motors are used

to activate both the

detergent and rinse

agent dispensers in a

Whirlpool dishwasher.

A blower motor

assembly used by

Jenn-Air to aid in

drying the dishes.

Element

Spring

Clip

Mounting

Bracket

Thermal

Limiter

Ground Wire

Grommets

Washer

Element

Retaining

Nuts

Dryer Heating

Element

Blower

Motor

Blower

Motor

Cover

Blower

Fan Wheel

Thermal

Protector

~

Blower

Wheel

located within the dishwasher tub area on most

models.

forced air blower to force the moisture out of the

dishwasher and through the vent.

PART VI

The powered vent is

located next to the

electronic control

behind the front panel

on the dishwasher.

Frigidaire allows heated air to

escape but keeps the water in the

dishwasher tub during the wash/

rinse cycles.

Electric will close during the irst ill cycle and remain

closed until the drying phase.

Inner Door

Control Panel

Active Vent

Spring

Shaft

Active Vent

Motor

Active Vent

Feedback Switch

Cam in Open Position

Cam

cycles, and in the drying phase the wax motors will open the vent.

Vent Closed Vent Open

Wax

Motor

5. Is the water valve inlet screen blocked? Turn off the water supply and remove the

water supply line to inspect the screen.

6. Is the water fill line that goes to the water valve kinked? Check visually.

7. Is the water siphoning out of the dishwasher while it is filling? Check the drain

hose installation.

8. Are the door latch switches working? Test switch(es) for continuity.

9. Is the float assembly stuck? Check for obstructions. Check assembly and test float

switch for continuity.

10. On electronic models, run the diagnostic test mode.

11. Check for loose or burned wires.

12. Check the float assembly and float switch.

Low Water Charge

1. Is there adequate water pressure to the water inlet valve? Pressure should be

between 15 and 120 pounds per square inch.

2. Is the water volume adequate? Take a quart container and fill it at the tap. The

water must fill the container in seven seconds or less.

3. Is the water valve inlet screen clean? Turn off the water supply and remove the

water supply line to inspect the screen.

4. On portable models, check the aerating snap adapter on the faucet.

5. Is the timer defective? Disconnect the electric supply and check the switch contacts

for continuity.

6. Is the electronic control functioning properly? Run the test mode.

7. Is the float switch improperly positioned? Is the switch defective? Disconnect the

electric supply and check the switch contacts for continuity.

8. Is the water fill line that goes to the water valve kinked? Check visually.

9. Check the service manual for the model you are servicing for the correct water level

in the tub when the fill cycle ends.

Poor Washability on the Upper Rack

1. Is the upper spray arm turning?

a. Are the holes in the spray arm plugged?

b. Check to see if the spray arm is split.

c. Is there uneven loading of the dishes?

d. Check the filter assembly for blockage.

e. Check the lower impeller to see if it is defective or blocked with debris.

f. Are any objects protruding down that might prevent the upper spray arm from

rotating?

2. Is the water charge okay?

PART VI

3. What is the temperature of the water entering the tub? Is the temperature at

140 degrees Fahrenheit?

4. Is the consumer using the proper amount of detergent?

5. Is the detergent dispenser functioning properly?

6. Are the dishes loaded properly? Ask the user to load the dishwasher so that you

can observe whether he or she is loading the dishwasher properly.

7. On some models you may have to check the filters for blockages.

Poor Washability in the Lower Rack

1. Is the lower spray arm turning?

a. Are the holes in the spray arm plugged?

b. Check to see if the spray arm is split.

c. Is there uneven loading of the dishes?

d. Is the spray arm binding on the housing?

e. Are any objects protruding down that might prevent the lower spray arm from

rotating?

2. Is the water charge okay?

3. What is the temperature of the water entering the tub? Is the temperature at

140 degrees Fahrenheit?

4. Is the consumer using the proper amount of detergent?

5. Is the detergent dispenser functioning properly?

6. Are the dishes loaded properly? Ask the user to load the dishwasher so that you

can observe whether he or she is loading the dishwasher properly.

7. On some models you may have to check the filters for blockages.

Poor Drying

1. Is the water hot enough? Check the water supply temperature. On certain models,

check to see if the cycle extender is functioning properly.

2. Is the heater working?

a. Check the wiring.

b. Check the timer or the electronic control board.

c. Check for the correct voltage.

d. Check the heater itself.

e. Check the heater fan assembly.

3. Is a wetting agent being used? Check wetting agent level.

4. Check the door baffle.

5. Check the vent system.

6. Suggest that the user open the door a little after the dry cycle has been completed.

Water Leaks at the Front of the Dishwasher

1. Is the spray arm turning? Is it split? Are any of the holes blocked with debris? If so,

this can cause the water to spill out of the tub.

2. Is the tub gasket in place? Check the corners especially. Worn tub or corner gaskets

will cause water to leak out of the corners.

3. Did you check the vent baffle gasket?

4. Some models have a corner gasket located in the inside front of the tub. Check to

see if it is in place.

5. Check to see if the tub is not overcharged with water. Too much water will spill

over the front tub flange.

6. Does the door close properly and tightly where the latch fits the strike?

7. On some models, are the gasket clips in place? These clips secure the gasket to the

tub.

8. Is the dishwasher loaded properly? Ask the user to load the dishwasher so that you

can observe whether he or she is loading the dishwasher properly.

9. Check to see if the dishwasher is draining properly. Inspect the drain hose where it

enters the drain.

10. Most important, is the dishwasher level?

11. Check the door liner for any cracks.

12. Check to see if the wetting agent dispenser is working properly. Too much wetting

agent will cause sudsing. Also check the gasket between the door and the dispenser.

Water Leaks at Sides, Top, or Bottom of Dishwasher

1. Check the side inlet tube on the side of the dishwasher.

2. Check to see if water is leaking out from the pump assembly.

3. Check the motor seals for water leakage.

4. Does the tub have a hole in it? Is the tub rusted out?

5. Check the nut on the water inlet port. Is it tight?

6. Are the heater element nuts tight?

7. Check to be sure that all screws are tight (motor and pump assembly, upper rack

screws, etc.).

The Dishwasher Cycle Will Not Advance (But the Lights Will Come On)

1. Is there voltage to the timer motor or electronic control board?

2. Are the cams in the timer rotating?

3. Is the dishwasher wired correctly?

4. Check to see if the timer is jammed.

5. Check to see if the selector switch is defective.

6. On electronic models, run the test mode.

PART VI

The Dishwasher Cycle Will Not Advance Past Start

1. Is the thermostat functioning properly? The thermostat must be flush with the

underside of the tub.

2. Check for correct timer settings.

The Detergent Cup Won’t Open

1. Is there voltage to the solenoid?

2. Is the detergent mechanism properly adjusted?

3. Check to see if there is any binding at any point.

4. Check to see if any dishes are preventing the detergent cup door from opening.

The Detergent Cup Won’t Close

1. Check the detergent cup actuator and cams.

2. Check to see if there is any binding at any point.

3. Is the detergent mechanism adjusted properly?

The Main Motor Won’t Operate

1. Check for continuity at the start and run windings. Check the motor for a shorted or

grounded winding.

2. Is there voltage to the motor?

3. Is the motor jammed? Check for foreign debris in the pump assembly.

4. Check to see if there are any loose wiring terminals or burned wires.

5. Check to see if the motor assembly is wired correctly.

The Motor Runs but Goes into Overload

1. Check the relay.

2. Is there any binding? Check the pump assembly for broken pieces of glass.

3. Be sure you have the correct voltage and the correct polarity.

4. Check to see if the motor windings are shorted.

5. Some models have a run capacitor. Test the run capacitor.

Door Liner Hits Side of Tub in Undercounter Models

1. Check to see if the tub is square.

2. Check the installation, and correct as needed.

Dishwasher Won’t Start

1. Is there voltage to the dishwasher? Check the plug, circuit breaker, or fuse box. Also

check the wires in the junction box, located behind the lower front panel.

2. Check the door switch for continuity of the switch contacts.

3. Check the selector switch for continuity of the switch contacts.

4. Check to see if the timer and selector switch have been wired correctly.

5. On electronic models, check the electronic control board.

6. Check for any wires that might have come off the timer or switches.

The Dishwasher Repeats the Cycle

1. Check the timer contacts; they should be open in the “off” position.

2. Check to see if the timer motor wires are shorted.

Wetting Agent Assembly Leaks

1. Open the door assembly, and check for leaks in the holding tank.

2. Check the wetting agent assembly for proper operation.

Water Siphons Out Through the Drain Pipe While the Dishwasher Is Trying to Fill

1. Is the drain line properly installed?

2. Check the installation instructions for proper installation.

Common Washability Problems

If there are no mechanical problems with the dishwasher’s operation and the complaints are

that the dishwasher will not clean the dishes properly or that the glassware is cloudy, etc.,

the next step will be to look at the best possible cause for the problem that the customer is

experiencing with the dishwasher. Then proceed to correct the problem. If necessary,

instruct the user on how to get better results from the dishwasher.

Poorly Cleaned Dishes

On occasion, there might be some food particles left on the dishes at the end of the cycle.

should be 140 to 150 degrees Fahrenheit as it enters the dishwasher tub.

water tap run before starting the dishwasher in order to clear the water line of any

cold water.

amount of dirty dishes to be cleaned.

detergent, at a minimum, in soft water. The dishwasher will require extra detergent

for greasy pans.

use and care manual so that the detergent is placed in the correct dispenser for the

cycle that is selected.

PART VI

1. Blocking the spray nozzle. If a large bowl or pot is placed over the center of the

lower rack, this will block the spray nozzle washing action when the lower rack

is pushed in.

2. Larger items that shield smaller items from the washing action.

3. Observe to see if there is a nesting of the bowls or silverware so that the water

cannot reach all surfaces.

4. The spray arms are blocked from turning, for example, tall items or an item that

fell through the racks.

5. If an item blocks the detergent dispenser from opening, this will not allow the

detergent to mix with the water.

instructions on how to load the dishes for proper cleaning.

15 and 120 pounds per square inch. After the fill has stopped, check the water level

in the tub. On most models, it should be even with the heating element in the

bottom of the dishwasher.

the dishwasher is operating.

used for laundry, baths, or showers.

completely.

Etching

Etching occurs when the glass is pitted or eroded. It appears as a permanent film on the

glass. The beginning stages of etching can be identified by an iridescent look—shades of

blue, purple, brown, or pink when the glass is held at an angle to the light. In the advanced

stages of etching, the glass surface appears frosted or cloudy.

combination of soft water, the alkalinity of dishwasher detergents, and heat.

damage is permanent. There is no way to predict what glassware might be affected—

it is not related to the cost or quality of the glass. To prevent etching from recurring:

140 degrees Fahrenheit.

into the dishwasher.

Discoloration

Discoloration (red, black, or brown) might be present on the dishwasher interior or dishes.

the dishwasher might turn red, black, or brown.

interior. With the dishwasher empty, turn to the rinse and hold cycle, and start the

dishwasher. During the fill, open the door and add 1/2 cup of rust remover to the

water. Allow the dishwasher to complete the cycle. Then start the dishwasher on the

normal wash cycle, with detergent but without dishes. To keep this condition from

returning, the customer might have to install special filters to remove the iron and

manganese. Use a rust remover according to the manufacturer’s recommendations

to remove the discoloration from the dishes and the glassware.

Lime Deposits on the Dishwasher Interior

eventually build up on the interior surfaces of the dishwasher.

the fill portion, open the door and add 1/2 cup of white vinegar to the water. Let

the dishwasher complete the remaining cycle. Do not use detergent. After the

cycle is completed, run the dishwasher with a regular load.

Suds or Foam in Dishwasher

an insufficient amount of detergent.

in the dishwasher detergent.

contain defoaming agents to break down the suds in the dishwasher water.

Only use detergents that are made for automatic dishwashers.

Darkened Aluminum

aluminum products.

PART VI

cleaner and to clean the item by hand. Never allow undissolved dishwasher

detergent to come in direct contact with the metal. Avoid placing aluminum items in

the lower rack, directly in front of the detergent dispenser.

Discoloration of Copper

when washed in the dishwasher, because of the heat and detergent alkalinity.

Cracking (Crazing) of China

surface of the china. It can occur when porous earthenware, good china that is very

old, or lower-quality china is exposed to heat and moisture.

characteristic is inherent in some clayware; this type of damage can occur during

use, handwashing, or automatic dishwashing.

Chipping of China and Crystal

might not be noticed until the dishes are removed from the dishwasher. When the

dishes are loaded into the dishwasher according to the manufacturer’s instructions,

there is nothing in the dishwasher that can chip the dishes. The dishes should only

come in contact with the cushioned vinyl-coated racks.

care manual for loading the dishwasher properly.

Metal Marks on Dishes and Glassware

dishwasher, a metal mark might result. This symptom appears as small black or

gray marks or streaks on dishes or glasses. However, most metal marks occur

during normal use, when the dishes come in contact with the flatware.

items from touching other dishes. There are products on the market that will

remove these marks. Have the user read over the use and care manual or check with

the manufacturer for this information.

Staining of Melamine Dinnerware

tea, and some fruit juices. If the surface is worn, it will stain more readily.

these stains. Instruct the customer to read over the use and care manual or check

with the manufacturer for this information.

Melting or Warping of Plastic Items

found in dishwashers without changing shape.

shape. In order to minimize or prevent plastic items from warping or melting,

instruct the user to do one of the following:

Discoloration of Silverplate

the silverplate has worn thin and the base metal is showing through. The combination

of dishwasher detergent and the lack of hand-toweling might result in discoloration

of this base metal.

silver polish or by soaking the item in vinegar for about 10 minutes. This is only a

temporary solution, however. Only a replating with silver by a jeweler will correct

the problem.

Tarnishing of Silverware (Sterling or Silverplate)

accelerated by the automatic dishwasher because of the higher water temperature

and because the usual hand-drying with a towel has been eliminated.

polishing is the only answer.

mayonnaise and eggs.

the item thoroughly as soon as possible after its use.

Bluish Discoloration of Stainless Steel

heat and the alkalinity of the automatic dishwasher detergent.

water or a stainless steel cleaner.

Corrosion or Rusting of Stainless Steel

corrosion will take place, as with ordinary steels. Certain foods will remove the

oxide film, such as table salt, vinegar, salad dressings, milk and milk products, fruits

PART VI

and juices, tomatoes and tomato products, and butter. However, if the stainless steel

is washed, rinsed, and dried thoroughly, the oxygen of the air will heal the breaks in

the oxide film and return the stainless property to the steel. But if food is not

washed off promptly, the air cannot heal the break, and corrosion will occur.

rinse or wash the flatware as soon as possible after use.

Dishwasher Maintenance

The dishwasher’s interior is normally self-cleaning. However, there are times when the

customer will have to remove food particles or broken glass in the bottom of the tub.

Instruct the customer to clean the bottom edge of the dishwasher tub, which is sealed off by

the gasket when the door is closed. Food and liquids drip on to this area when the

dishwasher is loaded. The control panel should be cleaned with a soft damp cloth. Tell the

customer not to use any abrasive powders or cleaning pads. Also, advise the customer to

read the use and care manual for proper maintenance procedures for his or her brand of

dishwasher. Dishwashers are designed to flush away all normal food soils that have been

removed from the dishes. However, on occasion, certain foreign objects, such as fruit pits,

bottle caps, etc., might collect in the openings of the pump. These items should be removed

periodically to avoid clogging the drain system. Also, on occasion, some of these foreign

objects can get caught in the spray arm openings and will have to be cleaned out. Check the

racks carefully to see if there are any nicks or cuts in the vinyl. These nicks and cuts can be

repaired. A liquid vinyl-repair material is available through the manufacturer or at any

appliance supply store.

Repair Procedure

Each of the following repair procedures is a complete inspection and repair process for a

single dishwasher component, containing the information you need to test a component

that might be faulty and then replace it, if necessary.

any dishwashers. Any improper installation, preventative maintenance, or repairs will

create a risk of personal injury, as well as property damage. Call the service manager if

installation, preventative maintenance, or the repair procedure is not fully understood.

Water Inlet Valve

The water inlet valve controls the flow of water into the dishwasher tub, and is solenoidoperated.

The typical complaints associated with water inlet valve failure (Figure 14-15) are:

When dealing with these complaints, perform the following steps:

cycles. Listen carefully, and you will hear if the water is entering the dishwasher.

On electronic models, turn off the electricity to the appliance and wait for two

minutes before turning it back on. If a fault code appears, look up the code. If the

dishwasher will not power up, locate the technical data sheet behind the control

panel or under the tub of the dishwasher for diagnostics information. On some

models you will need the actual service manual for the model you are working on

to properly diagnose the dishwasher. The service manual will assist you in properly

placing the dishwasher in the service test mode for testing the dishwasher

functions.

the appliance. Is the appliance installed properly? Is the voltage supply correct for

the dishwasher? Is the water turned on all the way? The voltage at the receptacle is

between 108 volts and 132 volts during a load on the circuit. Do you have the

correct polarity? (See Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Double-check to ensure that the

electrical supply has been disconnected before removing any service panels.

Another way to disconnect the electricity is at the fuse panel or the circuit breaker

panel. Turn off the electricity.

Gasket Screen

PART VI

panel must be removed (Figure 14-16). The bottom panel is held on with either two

or four screws, depending on the model. Remove the screws, and remove the panel.

remove the wire leads that connect to the solenoid coil from the wire harness

(Figure 14-17). These are slide-on terminal connectors attached to the ends of the

wire—just pull them off.

probes on the solenoid coil terminals (Figure 14-18). The meter should read

between 700- and 900-ohms resistance. If not, replace the water valve.

little water flow through the valve, inspect the inlet screen. If this screen is filled

with debris, it must be cleaned out. To accomplish this, use a small flat-blade

screwdriver and pry out the screen (Figure 14-19). Then wash out the screen,

making sure that all of the debris is removed. Reinstall the screen. Turn on the

water supply. Plug in the dishwasher. Allow the water to enter the tub to check the

flow rate of the water valve. The tub must be empty, because this will allow you to

check the flow rate properly. On a normal fill, the water line (on some models)

should be over the heating element within two minutes (Figure 14-20). When you

turn the dishwasher on and energize the water valve, if no water enters the

dishwasher tub, replace the water valve. If the water valve checks out okay, then

check the timer or electronic control board, float switch, and the wiring harness.

supply to the dishwasher. Then disconnect the water supply line from the inlet end

of the water valve and remove the fill hose from the outlet side (Figure 14-21). Next,

Adjustable toeplate

Removing the bottom

panel.

FIGURE 14-18

Connect meter probes

to the water valve

solenoid coil.

Inlet valve solenoid terminals

Wire leads from water

valve solenoid coil

Inlet valve solenoid terminals

PART VI

FIGURE 14-19

Removing water valve

inlet screen. Be

careful not to distort

the screen.

Screen

Float

Fill switch

Heater

Under

filled

Over

filled

Normal

fill

remove the screws that hold the water valve to the chassis of the dishwasher. To

install the new water valve, just reverse the disassembly procedure and reassemble.

Check for water leaks. If none are found, reinstall the bottom panel and restore the

electricity to the dishwasher.

dishwasher through its cycle.

Motor and Pump Assembly

The motor and pump assembly today utilizes a direct drive motor/pump assembly. This

means the motor drives the pump, which is attached to the motor. The shaft seal (Figure 14-22)

is a two-part seal needed to keep water from dripping onto the motor. This ceramic and

carbon seal is fragile. The water in the tub acts as a lubricant for the seal.

The typical complaints associated with pump and motor failure are:

leaking on the motor/pump assembly.

When dealing with these complaints, perform the

following steps:

the dishwasher through its cycles. Listen carefully, and

Water inlet valve

FIGURE 14-21

Disconnect the water

supply line.

FIGURE 14-22

Dishwasher motor and

pump seals. The

seals prevent water

from leaking out of

the dishwasher.

PART VI

you will hear if there are any unusual noises or if the circuit breaker trips. On

electronic models, turn off the electricity to the appliance and wait for two minutes

before turning it back on. If a fault code appears, look up the code. If the dishwasher

will not power up, locate the technical data sheet behind the control panel or under

the tub of the dishwasher for diagnostics information. On some models you will

need the actual service manual for the model you are working on to properly

diagnose the dishwasher. The service manual will assist you in properly placing the

dishwasher in the service test mode for testing the dishwasher functions.

the appliance. Is the appliance installed properly? Does the appliance have the

correct voltage? The voltage at the receptacle is between 108 volts and 132 volts

during a load on the circuit. Do you have the correct polarity? (See Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or at the circuit breaker panel. Turn off the electricity.

the bottom panel must be removed (see Figure 14-16). The bottom panel is held on

with either two or four screws, depending upon the model. Remove the screws and

remove the panel.

harness. Check the motor windings for continuity (Figure 14-23). Check for

resistance from the common wire lead to the run winding (Figure 14-24). Check

from the common to the wash winding (Figure 14-25).

To check for a grounded winding in the motor, take the ohmmeter probes and check

from each motor wire lead terminal to the motor housing (Figure 14-26). The

ohmmeter will indicate continuity if the windings are grounded (Figure 14-27).

If the motor/pump assembly shows signs of water leaking, replace the motor/

pump assembly as a complete unit. Most part manufacturers give a one-year

warranty on the motor/pump assembly. There is no advantage in tearing down the

motor/pump assembly to replace only one or two parts and receiving only a partial

warranty. Replacing the motor/pump assembly as a complete assembly will save

you time and money in the long run. If the motor/pump assembly checks out okay,

then check the timer and the motor relay (if the model you are repairing has one)

and check for a kinked or plugged drain line.

dishwasher. As shown in Figure 14-28, remove the wash tower and spray arm

assembly. If there is a filter, remove it also. Remove the motor wiring leads from

the wiring harness. Then remove the drain line from the pump assembly.

Reach underneath the tub and rotate the four pump hold-downs 90 degrees inward

(Figure 14-29). You are now ready to remove the motor/pump assembly. Lift the

motor/pump assembly out from the inside of the tub (Figure 14-30). Keep the work

area dry to help prevent electrical shocks.

Multitester

Motor

terminal

wires

FIGURE 14-23

Check the motor

windings for

continuity.

FIGURE 14-24

Check from the

common to the drain

winding.

White

White

Black

Blue

Red

Blue - run winding

White - common

Red - drain winding

Black - wash winding

PART VI

FIGURE 14-25

Check from the

common to the wash

winding.

FIGURE 14-26

Check for the

grounded motor.

White

White

Black

Blue

Red

White

White

Black

Blue

Red Blue - run winding

White - common

Red - drain winding

Black - wash winding

(a)

(b)

Motor

housing

Ohmmeter

White

Black

Blue

Red

FIGURE 14-27

The grounded motor.

Spray arm

Wash tower

PART VI

Upper

spray arm

Water column

Nozzle cap

Washer

Lower

spray arm

Sump

guard

Power clean

module

and motor

Motor

hold-downs

FIGURE 14-29

An exploded view of a

dishwasher motor/

pump assembly.

FIGURE 14-30

Remove the motor/

pump assembly. After

removal, inspect the

tub for rust.

reverse the order of step 6. Before restoring the electricity to the dishwasher, pour a

gallon of water into the tub and check for leaks underneath the tub. Restore the

electricity to the dishwasher, and run the dishwasher through a cycle. Check for

leaks again. If no leaks are found, reinstall the bottom panel.

Dishwasher Timer

Electromechanical timers are utilized for controlling the different cycles. The timer assembly

is driven by a synchronous motor in incremental advances. It controls and sequences the

numerous steps and functions involved in each cycle of a dishwasher.

On models with an electronic control board, refer to the service manual for proper

removal and testing. On models that use an electronic control along with a sequence switch,

refer to the service manual for proper removal and testing.

The typical complaints associated with dishwasher timer failure are:

When dealing with these complaints, perform the following steps:

cycles. Before you change the timer, check the other components controlled by the

timer.

operation of the appliance. Is the appliance installed properly? Does the appliance

have the correct voltage? The voltage at the receptacle is between 108 volts and 132

volts during a load on the circuit. Do you have the correct polarity? (See Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or circuit breaker panel. Turn off the electricity.

console to access the timer (Figure 14-31). Turn the timer knob counterclockwise to

remove it from the timer shaft, and slide the indicator dial off the shaft. Remove the

console panel from the dishwasher. On some models, the latch handle knob will

also have to be removed.

PART VI

FIGURE 14-31

Remove the screws to

access the control

panel.

Remove screw

Remove screw

Remove screw

Remove screw

Console

motor terminals (Figure 14-32). The meter should indicate some resistance. If not,

replace the timer. If the motor checks out, then check the door latch switch, cycle

extender relay, and the float switch assembly.

Timer motor terminals

Timer

FIGURE 14-32

Attach the meter

probes and test for

continuity.

FIGURE 14-33

Removing the timer.

Timer plug

Timer

Timer mounting screws

(Figure 14-33). Remove the wire lead terminals from the timer. Mark the wires as to

their location on the timer. Some timers have a disconnect terminal block instead of

individual wires, which makes it easier to remove the timer wires.

and reassemble. Reinstall the console panel, and restore the electricity to the

dishwasher. Test the dishwasher operation.

The Dishwasher Door Is Hard to Close

Check the latch assembly, door gaskets, tub gaskets, and on some models, the corner gaskets.

The typical complaints associated with a dishwasher door being hard to close are:

When dealing with these complaints, perform the following steps:

the appliance. Is the appliance installed properly? Be sure that the dishwasher door

is not binding against the side cabinet.

Next, run the hot water faucet closest to the dishwasher to flush out the supply line.

Then turn the timer to the normal wash cycle with heated dry, and let it run through

the entire cycle. By doing this procedure, the gasket will soften enough to form itself

PART VI

to the tub while it is compressed. This should make it easier to latch the door. If not,

adjust the latch assembly. If it is still too hard to close, replace the door gasket.

hold the old gasket in place (Figure 14-34). On some models, the gasket is pressed

into the inner door assembly. Remove the inner panel from the dishwasher, and pull

off the gasket from the panel (Figure 14-35). Soak the new gasket in warm water to

make it more flexible.

door, and test to see if the door latches without pushing hard against it.

water leaking out the door. Most models have a baffle, or tub, gasket. If the

dishwasher that you’re working on has one, check to make sure it is not defective.

The tub gasket is located either on the tub or behind the inner door panel.

Dishwasher Heating Element

Most dishwashers use a calrod heating element to heat the water and dry the dishes. The

element consists of a tungsten wire packed in magnesium oxide and surrounded by a

coated stainless steel sheath. The resistance and voltage can be measured with a multimeter

to verify if the element is functioning properly.

FIGURE 14-34

Removing dishwasher

door gasket.

To replace

Clip

To remove

Gasket

Insert screwdriver

blade under

flange of clip;

pry outward

Apply pressure

to flange of

clip; press

into place

FIGURE 14-35

Pull off the gasket,

being careful not to

damage the door liner.

Door gasket Track

Door

The typical complaints associated with the heating element are:

When dealing with these complaints, perform the following steps:

the dry cycle. On electronic models, turn off the electricity to the appliance and wait

for two minutes before turning it back on. If a fault code appears, look up the code.

If the dishwasher will not power up, locate the technical data sheet behind the

control panel or under the tub of the dishwasher for diagnostics information. On

some models you will need the actual service manual for the model you are

working on to properly diagnose the dishwasher. The service manual will assist

you in properly placing the dishwasher in the service test mode for testing the

dishwasher functions.

the appliance. For example, check the Energy Saver switch. Is it set for heat-dry? Is

the appliance installed properly? Does the appliance have the correct voltage? The

voltage at the receptacle is between 108 volts and 132 volts during a load on the

circuit. Do you have the correct polarity? (See Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or the circuit breaker panel. Turn off the electricity.

PART VI

bottom panel must be removed (see Figure 14-16). The bottom panel is held on with

either two or four screws, depending on the model. Remove the screws and remove

the panel.

wires from the heating element terminals (Figure 14-37). These are slide-on terminal

connectors attached to the ends of the wire. Use the ohmmeter to check for

continuity between the two element terminals (Figure 14-38). If the meter indicates

no continuity between the terminal ends, replace the heater.

To check for a shorted-out heating element, take one end of the ohmmeter probe

and touch the element terminal; then, with the other probe, touch the sheath (outer

cover of element), shown in Figure 14-39. If the meter indicates continuity, the

element is shorted out and should be replaced.

already removed from the heater terminals), unscrew the locknuts that hold the

element in place. From inside the tub, remove the heating element (Figure 14-40).

procedure and reassemble. Then test the new element by repeating step 1.

Cycle Selector Switch

The dishwasher cycle selector switch allows the consumer to select the various cycles and

options for that model dishwasher. When the consumer turns on the timer to start the

Section A-A

Helix A

A

Sheath

Electrical insulation

Heating element

FIGURE 14-36

The dishwasher

heating element.

dishwasher cycle, if the cycle selector switch buttons are not selected correctly, the dishwasher

will not perform to the consumer’s satisfaction.

The typical complaints associated with the cycle selector switch are:

FIGURE 14-39

To check for a

shorted-out element,

attach the meter

probe to one terminal

and attach the other

probe to the sheath.

Heating element

terminals Heating

element

terminals

terminals from the heater element.

probes to the heater terminals.

Terminal cover

PART VI

FIGURE 14-40

Removing the heating

element.

Locknut

When dealing with these complaints, perform the following steps:

select different cycles. On electronic models, turn off the electricity to the appliance

and wait for two minutes before turning it back on. If a fault code appears, look up

the code. If the dishwasher will not power up, locate the technical data sheet behind

the control panel or under the tub of the dishwasher for diagnostics information.

On some models you will need the actual service manual for the model you are

working on to properly diagnose the dishwasher. The service manual will assist

you in properly placing the dishwasher in the service test mode for testing the

dishwasher functions.

the appliance. For example, is there any physical damage to the component? Did

you check for the correct voltage? The voltage at the receptacle is between 108 volts

and 132 volts during a load on the circuit. Do you have the correct polarity? (See

Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or circuit breaker panel. Turn off the electricity.

the top inside edge of the door (see Figure 14-31). On some models, you might have

to remove the door latch knob in order to completely remove the control panel.

the switch. Just remember—you will have to identify the wires according to the

wiring diagram in order to reinstall them back on the cycle selector switch properly.

Take your ohmmeter, and check for continuity on the switch contacts; press the

switch that coincides with the terminals that are being checked (Figure 14-42). At this

point, you have to use the wiring diagram to identify the switch contacts.

screws that hold the component to the control panel (Figure 14-43).

the disassembly procedure and reassemble. Remember—you will have to identify

the wires according to the wiring diagram in order to reinstall them back on the

cycle selector switch properly.

FIGURE 14-41

Selecting a cycle.

PART VI

Control panel

Multitester Switch terminals

Selector switch

Dishwasher Door Switch

Sometimes, the dishwasher door latch assembly and/or switch malfunctions and the door

will not close properly, or the door switch will prevent the dishwasher from coming on at

all. When dealing with these complaints, perform the following steps:

dishwasher door and turning the timer dial to start the wash cycle. On electronic

models, turn off the electricity to the appliance and wait for two minutes before

turning it back on. If a fault code appears, look up the code. If the dishwasher will not

power up, locate the technical data sheet behind the control panel or under the tub of

the dishwasher for diagnostics information. On some models you will need the actual

service manual for the model you are working on to properly diagnose the dishwasher.

The service manual will assist you in properly placing the dishwasher in the service

test mode for testing the dishwasher functions.

the appliance. Is the appliance installed properly? Does the appliance have the

correct voltage? The voltage at the receptacle is between 108 volts and 132 volts

during a load on the circuit. Do you have the correct polarity? (See Chapter 6.) Is

there any physical damage to the component?

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or circuit breaker panel. Turn off the electricity.

the top inside edge of the door (see Figure 14-31). On some models, you might have

to remove the door latch knob in order to completely remove the control panel.

FIGURE 14-44

Closing the door and

running the

dishwasher.

PART VI

(Figure 14-45). Close and latch the door. With your ohmmeter, check for continuity

between the two terminals on the switch. Then open the door latch and check for no

continuity between the terminals. If the switch fails these tests, replace the switch.

Remove the switch.

procedure and reassemble. Then reconnect the electricity and test the dishwasher.

Float and Float Switch

Sometimes, the dishwasher float and the float switch malfunctions and water will not enter

the tub, or water overfills and spills onto the floor. When dealing with these complaints,

perform the following steps:

turning the timer dial to start the wash cycle. On electronic models, turn off the

electricity to the appliance and wait for two minutes before turning it back on. If a

fault code appears, look up the code. If the dishwasher will not power up, locate the

technical data sheet behind the control panel or under the tub of the dishwasher for

OHMS

6 8 10 15 20 30 50 100

200

5 4 3 2 1 0

OHMS

DC

AC

DC

AC

7 10 15 20

5 4 2 3 1 0

30 50 100 200 500

250

50

10

200

40

8

150

30

6

100

20

4

50

10

2

25

5

10

25

20

4

8

20

15

3

6

15

10

8

10

2

4

10

5

1

2

5

642 0 2 4 6

VOLT-OHM MILLIAMMETER

RESET 5A

DC AC

DC

ALL TERMINALS 10V MAX

􀀂

L P ( )

1VDC

2.5V

AMP CLAMP

10V

100V

2.5V

50mA

250V

500V

1000V

OFF

TRANSIT

L P ( )

0.5mA

5mA

AMPS

50mA

500mA

OUTPUT

150 VDC

MAX

?

OHMS ADJ

50mA 5A

250mV

dB

NC

COM.

FIGURE 14-45

The dishwasher latch

assembly in the

closed position.

diagnostics information. On some models you will need the actual service manual

for the model you are working on to properly diagnose the dishwasher. The service

manual will assist you in properly placing the dishwasher in the service test mode

for testing the dishwasher functions.

the appliance, as was done in the previous sections. Did you check for the correct

voltage? The voltage at the receptacle is between 108 volts and 132 volts during a

load on the circuit. Do you have the correct polarity? (See Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or the circuit breaker panel. Turn off the electricity.

that the float moves freely up and down. If there is any soap buildup around the

float, clean it off.

Float

FIGURE 14-46

Inspecting the loat

assembly. Check for

soap buildup around

the stem and inside of

the loat.

PART VI

FIGURE 14-47

Testing the loat

bracket

Continuity tester

Float

switch

terminals

bottom panel must be removed (see Figure 14-16). The bottom panel is held on with

either two or four screws, depending on the model. Remove the screws, and remove

the panel.

(Figure 14-47). Remove the wires from the terminals, and test for continuity. Lift the

float—there should be no continuity. Let the float rest, and you should have

continuity. If the test fails, replace the float switch.

screws that hold the switch in place (Figure 14-48).

disassembly procedure and reassemble. Then reconnect the electricity and test a

dishwasher cycle that fills the dishwasher.

Wetting Agent and Detergent Dispensers

The dishwasher detergent dispenser will operate by electrical or mechanical means. On some

models, the detergent dispenser will operate by a bimetal, motor-driven, or mechanical lever

working off the timer assembly. The dishwasher wetting agent dispenser will dispense

the wetting agent by an electrical or mechanical lever too. On some models the detergent and

wetting agent dispensers are combined into one assembly.

The typical complaints associated with the wetting agent and detergent dispensers are:

When dealing with these complaints, perform the following steps:

cycles. Make sure that the detergent dispenser door is not blocked by dishes. Also

check the wetting agent level in the dispenser. On electronic models, turn off the

electricity to the appliance and wait for two minutes before turning it back on. If a

fault code appears, look up the code. If the dishwasher will not power up, locate the

technical data sheet behind the control panel or under the tub of the dishwasher for

diagnostics information. On some models you will need the actual service manual

for the model you are working on to properly diagnose the dishwasher. The service

manual will assist you in properly placing the dishwasher in the service test mode

for testing the dishwasher functions.

the appliance. For example, is there any physical damage to the component? Is the

water in the dishwasher at the correct level? Did the consumer fill the wetting agent

dispenser with wetting agent? Did you check the voltage? The voltage at the

receptacle is between 108 volts and 132 volts during a load on the circuit. Do you

have the correct polarity? (See Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or circuit breaker panel. Turn off the electricity.

Float assembly

Switch

Screw

“O” Ring

Collar

Screw

Float

FIGURE 14-48

An exploded view of

the loat switch

assembly.

PART VI

the top inside edge of the door (see Figure 14-31). On some models, you might

have to remove the door latch knob in order to completely remove the control

panel. Then reconnect the electricity, latch the dishwasher door, and test a dishwasher

cycle. A cam follower next to the timer will actuate the detergent dispenser when the

wash cycle is in the second wash. The cam follower will engage the draw bar

(Figure 14-49) and pull up on the detergent lid latch, releasing the detergent lid and

allowing the detergent to enter into the wash cycle. In the final rinse cycle, the same

operation occurs to release the wetting agent from the wetting agent dispenser.

Draw bar

spring

Detergent lid

Lid spring

Latch

Slide latch

spring

Actuator

Draw bar

lower

FIGURE 14-49

A side view of the

detergent dispenser.

cover and drawbar spring. Now begin to remove the upper and lower drawbars by

aligning the lower drawbar holes with the locating tabs. In Figure 14-50b, you will

note that the locating tabs will align with their respective holes while removing the

drawbars. Remember where they reattach when it comes to reassembly later. Begin to

slide the drawbars apart, as shown in Figure 14-50c. Next, you will have to remove the

wetting agent cap by turning the cap and seal assembly counterclockwise, as in

Figure 14-50d. Using a ¾-inch socket wrench, begin to insert it into the wetting agent

dispenser locking tabs, shown in Figure 14-50d, to release the wetting agent dispenser

from the inner door liner. Now you are ready to remove the wetting agent dispenser

actuator. Spread apart the two locking tabs, as shown in Figure 14-50e, and remove the

upper and lower slides from the dispenser actuator. Next remove the diaphragm spring

and diaphragm (Figure 14-50e). To remove the detergent door and actuator assembly,

use a small flat-blade screwdriver to depress and release the lower tabs, noting the

position of the door latch level through the hole in the lower slide (Figure 14-50f).

Finally, remove the upper slide, slide spring, and the lower slide (Figure 14-50g).

Drawbar spring

Drip cover

(a)

cover and drawbar spring.

Locking tabs

Drawbar

assembly

Lower

drawbar

Locating

tab

Upper slide

locating hole

Upper

drawbar

Locking

tab

Locating

tab

Upper slide

locating hole

Locking

tab

(b)

alignment of the locating tabs.

PART VI

Upper

drawbar

Lower

drawbar

(c)

(d)

Wet agent

cap

Seal

Wet agent

cap opening

3/4” OR

Socket

Special

tool

Wet agent

dispenser

locking tabs

Wet agent

dispenser

locking tabs

Wet agent

dispenser

assembly

(e)

Lower

slide

Upper

slide

Wet agent

dispenser

actuator

Wet agent

Diaphragm dispenser

spring

Diaphragm

Metering

chamber Locking

tabs (f)

Hook

Lever

Detergent

door latch

snap

Detergent

door latch

Upper

tabs Detergent door

actuator assembly

Lower

slide opening

Door

latch lever

Lower

tab

and lower drawbars. To

remove, follow the

direction of the arrows.

diaphragm spring, and the diaphragm

from the wetting agent dispenser.

and detergent door latch. Remember the tab alignment when

dissembling and reassembling.

Upper

slide

Lower

slide

Detergent door

actuator

Slide spring

(g)

The upper slide, slide

spring, lower slide,

detergent door

actuator, and spring

will be removed last in

disassembly; it will be

the irst step in

reassembly.

PART VI

just reverse the disassembly procedure and reassemble. Then reconnect the

electricity and test the dishwasher.

Water Heater Operating Thermostat or Thermistor

The bimetal thermostat is secured and located underneath the tub. The purpose of the

thermostat is to either act as a safety net to prevent overheating or is used to raise the water

temperature in the tub. The thermistor is used in some models to sense the water temperature

on certain cycles. The thermistor sends signals back to the electronic control.

The typical complaints associated with the water heater operating thermostat are:

When dealing with these complaints, perform the following steps:

cycles. Take the temperature of the water in the dishwasher tub when the

dishwasher is in the wash cycle. Also check the hot water temperature at the sink. It

should be between 120 to 140 degrees Fahrenheit. On electronic models, turn off the

electricity to the appliance and wait for two minutes before turning it back on. If a

fault code appears, look up the code. If the dishwasher will not power up, locate the

technical data sheet behind the control panel or under the tub of the dishwasher for

diagnostics information. On some models you will need the actual service manual

for the model you are working on to properly diagnose the dishwasher. The service

manual will assist you in properly placing the dishwasher in the service test mode

for testing the dishwasher functions.

the appliance. Test the hot water temperature at the sink. The water temperature

should be around 120 to 140 degrees Fahrenheit. The purpose of this thermostat is

to delay the wash cycle until the water temperature reaches between 135 and 145

degrees Fahrenheit. The rule of thumb is it takes 20 minutes to raise the water

temperature two degrees. The thermostat will then close and complete the timer

motor circuit, allowing the dishwasher cycle to continue. Did you check the

voltage? The voltage at the receptacle is between 108 volts and 132 volts during a

load on the circuit. Do you have the correct polarity? (See Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or circuit breaker panel. Turn off the electricity.

thermostat terminals, the bottom panel must be removed (see Figure 14-16). The

bottom panel is held on with either two or four screws, depending on the model.

Remove the screws, and remove the panel. Inspect the wiring connections first.

(Figure 14-51) underneath the tub, and remove the wires from the terminals.

Remove the thermostat from the dishwasher tub. Take a metal pot of water, and

heat it up on the range until the temperature reaches between 150 and 160 degrees

Fahrenheit. Next, set your multimeter to the ohm scale. Test the thermostat before

placing it against the metal pot—it should read infinite resistance. Now place the

thermostat against the metal pot of hot water—the thermostat should close and the

multimeter will read continuity. If not, replace the thermostat.

remove the wires from the terminals. Test the thermistor using the multimeter, and

set the meter on the ohm scale. Write down the resistance reading and check it

against the technical data sheet for the proper rating. If the resistance does not

match the technical data sheet, replace it.

new thermostat or thermistor, just reverse the disassembly procedure and

reassemble. Then reconnect the electricity and test the dishwasher.

High-Limit Heater Thermostat

The high-limit heater thermostat is a protective device that will prevent the heater from

overheating.

The typical complaints associated with the high-limit heater thermostat are:

Water heater

operating thermostat

Thermostat located

underneath the

dishwasher tub

FIGURE 14-51

The heater operating

thermostat will allow

the water to heat up

to 145 degrees

Fahrenheit.

PART VI

When dealing with these complaints, perform the following steps:

cycles. The purpose of this thermostat is to act as a safety switch to disconnect the

heater in the event the temperature rises above 185 degrees Fahrenheit. On

electronic models, turn off the electricity to the appliance and wait for two minutes

before turning it back on. If a fault code appears, look up the code. If the

dishwasher will not power up, locate the technical data sheet behind the control

panel or under the tub of the dishwasher for diagnostics information. On some

models you will need the actual service manual for the model you are working on

to properly diagnose the dishwasher. The service manual will assist you in properly

placing the dishwasher in the service test mode for testing the dishwasher

functions.

the appliance. Did you check the voltage? The voltage at the receptacle is between

108 volts and 132 volts during a load on the circuit. Do you have the correct

polarity? (See Chapter 6.)

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or circuit breaker panel. Turn off the electricity.

thermostat terminals, the bottom panel must be removed (see Figure 14-16). The

bottom panel is held on with either two or four screws, depending on the model.

Remove the screws, and remove the panel. Inspect the wiring connections first.

thermostat (Figure 14-52) underneath the tub, and remove the wires from the

terminals. Remove the thermostat from the dishwasher tub. Take a metal pot of

water, and heat it up on the range until the temperature reaches 185 degrees

Fahrenheit. Next, set your multimeter to the ohm scale. Test the thermostat before

placing it against the metal pot of hot water—the multimeter will read continuity.

Now place the thermostat bimetal section against the metal pot of hot water—the

thermostat should open and the multimeter will read infinite resistance. If not,

replace the thermostat.

reverse the disassembly procedure and reassemble. Then reconnect the electricity

and test the dishwasher.

Dishwasher Motor Start Relay

The dishwasher motor start relay is a solenoid-activated relay used to start the dishwasher

motor in some models.

The typical complaints associated with the motor start relay are:

1. The dishwasher motor will not start.

2. The dishwasher motor hums and shuts off on overload.

When dealing with these complaints, perform the following steps:

motor does not start, turn the dishwasher off immediately. On electronic models,

turn off the electricity to the appliance and wait for two minutes before turning it

back on. If a fault code appears, look up the code. If the dishwasher will not power

up, locate the technical data sheet behind the control panel or under the tub of the

dishwasher for diagnostics information. On some models you will need the actual

service manual for the model you are working on to properly diagnose the

dishwasher. The service manual will assist you in properly placing the dishwasher

in the service test mode for testing the dishwasher functions.

the appliance. Is there electricity to the dishwasher? The voltage at the receptacle is

between 108 volts and 132 volts during a load on the circuit. Do you have the

FIGURE 14-52

The high-limit heater

thermostat location.

PART VI

correct polarity? (See Chapter 6.) The purpose of the motor start relay is to protect

the dishwasher motor. This current-sensitive relay will close the contacts when the

current increases for about one or two seconds when the motor begins to start.

When the dishwasher motor starts and runs, the current will decrease in the motor

start relay, thus opening the contacts.

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or circuit breaker panel. Turn off the electricity.

thermostat terminals, the bottom panel must be removed (see Figure 14-16). The

bottom panel is held on with either two or four screws, depending on the model.

Remove the screws, and remove the panel. Inspect the wiring connections first.

dishwasher (Figure 14-53) by removing the screw that holds the relay in place.

Disconnect the wires from the relay. Set your ohmmeter to the R x 1 scale, and

measure the coil’s resistance. The coil will read less than 1 ohm if it is good. Next,

attach your ohmmeter probes to the relay contacts; you will check the relay contacts

for continuity by turning the relay upside down. If you do not know which way is

up or down on the relay, there is an arrow and the word “up” stamped on the relay.

The motor start relay contacts should be closed, and the ohmmeter will read zero

resistance. With the ohmmeter probes still attached to the relay, turn the relay rightside-

up to check the continuity of the contacts—the relay contacts will be open, and

the ohmmeter will read infinite resistance.

Screw

FIGURE 14-53

The dishwasher motor

start relay is located

behind the lower front

panel.

reverse the disassembly procedure and reassemble. Then reconnect the electricity

and test the dishwasher.

Electronic Control Board, Display Board, and Touch Pad Panel

The electronic control board monitors all of the functions and cycles. When servicing this

component, check all wiring for loose connections at the wiring harness, connector plugs,

and the pins. Loose connections are common and most likely will cause the dishwasher to

operate erratically.

The typical complaints associated with the electronic control board, display board, and

touch pad panel are:

When dealing with these complaints, perform the following steps:

the electricity to the appliance and wait for two minutes before turning it back on. If

a fault code appears, look up the code. If the dishwasher will not power up, locate

the technical data sheet behind the control panel or under the tub of the dishwasher

for diagnostics information. On some models you will need the actual service

manual for the model you are working on to properly diagnose the dishwasher. The

service manual will assist you in properly placing the dishwasher in the service test

mode for testing the dishwasher functions.

the appliance. Is there electricity to the dishwasher? The voltage at the receptacle is

between 108 volts and 132 volts during a load on the circuit. Do you have the

correct polarity? (See Chapter 6.) Check for a blown thermal fuse in the circuit.

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or circuit breaker panel. Turn off the electricity.

PART VI

the top inside edge of the door (see Figure 14-31). On some models, you might have

to remove the door latch knob in order to completely remove the control panel.

able to run the dishwasher diagnostic test mode, check the different functions of the

dishwasher. Use the technical data sheet for the model you are servicing to locate

the test points from the wiring schematic. Do not forget to check all wiring

connections and wiring. Using the technical data sheet, test the key pad matrix,

display board LEDs, input voltages, and output voltages on the electronic control

board.

remove the defective component, remove the covers that shield the control, and

then remove the screws that secure the boards to the control panel (Figure 14-54).

Disconnect the connectors from the electronic control board, display board, or the

touch pad panel. On some models, the touch pad panel might be glued to the

control panel. Once you remove the defective part, you will have to replace it with a

new one.

Control board cover

Electronic

control board

Display board

shield

Display

board

Vent

Control panel

Touch pad panel

or touch pad panel, just reverse the disassembly procedure and reassemble.

Reinstall the console panel, and restore the electricity to the dishwasher. Test the

dishwasher operation.

Turbidity Sensor

The turbidity sensor (Figure 14-55a and b) is located on the motor and pump assembly. Its

main purpose is to measure the amount of suspended food particles in the wash water. If it

senses food particles, on some models, an extra wash cycle will be added to the length of

the dishwashing cycle.

The typical complaints associated with the turbidity sensor are:

cycles. On electronic models, turn off the electricity to the appliance and wait for two

minutes before turning it back on. If a fault code appears, look up the code. If the

dishwasher will not power up, locate the technical data sheet behind the control

Turbidity sensor

used to detect food particles in the wash

water.

assembly.

PART VI

panel or under the tub of the dishwasher for diagnostics information. On some

models you will need the actual service manual for the model you are working on to

properly diagnose the dishwasher. The service manual will assist you in properly

placing the dishwasher in the service test mode for testing the dishwasher functions.

the appliance. Is the appliance installed properly? Does the appliance have the

correct voltage? The voltage at the receptacle is between 108 volts and 132 volts

during a load on the circuit. Do you have the correct polarity? (See Chapter 6.) Is the

water hot enough?

electricity. This can be done by pulling the plug out of the wall receptacle. Be sure

that you only remove the dishwasher plug. Or disconnect the electricity at the fuse

panel or at the circuit breaker panel. Turn off the electricity.

the bottom panel must be removed (see Figure 14-16). The bottom panel is held on

with either two or four screws, depending upon the model. Remove the screws and

remove the panel.

(Figure 14-55b), remove the wires and test the sensor, using the ohms scale on the

multimeter. Verify the reading against the technical data sheet or the service

manual for proper specifications. Before removing the turbidity sensor, place a pan

underneath to collect the water. To remove the sensor on this model, just twist and

turn and pull out.

order of step 5. Before restoring the electricity to the dishwasher, pour a gallon of

water into the tub and check for leaks underneath the tub. Restore the electricity to

the dishwasher, and run the dishwasher through a cycle. Check for leaks again. If

no leaks are found, reinstall the bottom panel.