Danby DDW398W User manual

SERVICE MANUAL
COUNTER-TOP DISHWASHER
DDW398W,DDW399W
DANBY PRODUCTS LTD.
GUELPH, ONTARIO N1H6Z9
DANBY PRODUCTS INC.
FINDLAY, OH 45839

Contents
1. Circuit Diagram___________________________________________1
2. Tools and Test Equipment___________________________________2
3. Troubleshooting___________________________________________3
4. Performance Check: Loading_________________________________5
5. Performance Check: Detergent and Rinse Agent__________________7
6. Power Connections_________________________________________8
7. Removing Outer Casing and Control Panel______________________9
8. Inner Wiring Connections Check______________________________10
9. Door Latch Mechanical_____________________________________11
10. Timer___________________________________________________12
11. Power Switch and Option Switch_____________________________15
12. Water Inlet Valve_________________________________________16
13. Pressure Switches_________________________________________18
14. Pump and Motor Assembly__________________________________19
15. Heating Element and Safety Thermostat________________________20
16. Normal Thermostat________________________________________21
17. Hose Connector___________________________________________22
18. Rinse Agent Dispenser______________________________________23
19. Parts List_________________________________________________24
20. Exploded View____________________________________________29

1.Circuit Diagram
1.

2. Tools and Test Equipment
Hand Tools
A basic compliment of hand tools i.e. flat and phillips head screw drivers,
socket set, pliers and wire striper / crimping tool.
A basic volt ohm meter (VOM) will also be required for circuit and
component testing.
2

3. Troubleshooting
Problem Possible Cause Repair Procedure
1.Pump and timer do not run Power receptacle defective Check receptacle
(power pilot is not illuminated) Power cord defective Check power cord
Open wire to timer Check timer
Open door latch switch Check wiring and connection
Power switch defective
Check option switch and power switch
2. Too little or no water fill Kinked fill hose Check inlet hose
Low houes water pressure check faucet
Blocked inlet valve or faucet Check inlet valve and faucet
Open or defective pressure switch See pressure switch
3. Water does not shut off Pressure switch defective See pressure switch
water inlet valve stuck open See inlet valve
4. Water pumping out before Pressure switch defective See pressure switch
washing dishes.
5. Timer does not advance Poor terminal connection on timer See timer
Defective timer See timer
6. Water does not pump out Drain hose kinked or blocked Check drain hose
Resistance or capacitance defect See pump and motor assembly
7. Dishwasher leaks Dishwasher not level Adjust leveling legs
Door not closing tightly Adjust latch strike
Crack in hose connection Replace hose
Gasket damaged Replace gasket
Inlet valve connector loose or defective Check water inlet valve
Loose connection between pump & sump Reconnect using encapsulant
Pump body damaged Replace pump and motor assembly
Pump seal defective See pump and motor assembly
8. Detergent remains in detergent
cup Detergent is old and caked See detergent and rinse agent
Dishes block water from detergent cup See loading dishes
No or low water See #2
9. Rinse agent dispenser does not No rinse agent in dispenser Check rinse agent level
release rinse agent Solenoid inoperative check rinse agent dispenser
Open timer contacts Check timer
10. Rinse agent dispenser leaks Dispenser gasket defective Replace gasket
Dispenser tank cracked Replace dispenser
11. Poor washing results Improper loading See loading dishes
Detergent old, incorrect type or amount See detergent and rinse agent
Improper cycle selection Choose proper cycle
Kinked or cloged drain hose Check drain hose
Foreign material in wash system Check wash system
Foreign material in spray arm Clean wash arm
Rinse agent leaks into tub during wash Replace dispenser
12. Poor drying Rinse agent not used Fill rinse agent dispenser
heating unit inoperative See heating element
3

3. Troubleshooting Cont.
Problem Possible Cause Repair Procedure
13. Condensation on door Some condensation is normal Cause- steam vent on door
14. Dishwasher door is difficult to Door gasket emersion Pull gasket into slot
open or close Door linkage bent See door latch assembly
Door hook deflection See door latch assembly
15. Noise during operation Dishes rattling See loading dishes
Drain pump viberating See pump and motor assembly
Foreign object in pump Check wash pump
16. Hose connector leaks Silcon sleeve worn See hose connectors
Connector hose washer defective Replace washer
Connector gasket damaged Replace connector gasket
4

4. Performance Check: Loading
Many performance problems that commonly occur in dishwashers are not due to mechanical defects. Problems with
poor washing results can often be resolved without making repairs.
The procedures in this manual are designed to help you eliminate performance problems before you begin checking
and testing the dishwasher’s components. To get the best results from the dishwasher it is necessary to form good
loading habits. If the dishwasher seem to be running correctly, but does not get the dishes really clean, check to be
sure it is being loaded properly. The owner’s manual gives detailed instructions on this procedure.
5

PROCEDURE
Loading dishwasher
6

5. Performance Check: Detergent and rinsing agent
Water and detergent are major factors for good dishwasher performance. Water pressure, hardness
and temperature also play vital roles in getting good results. The correct detergent, in proper amounts,
is equally important. The water hardness in your area will effect the amount of detergent needed to get
clean dishes.
PROCEDURE
Checking detergent
Step 1: For personal safety Step 2: Only use detergent intended Step 3: This dishwasher has a rinse
always exercise caution when specifically for automatic dishwashers. agent dispenser, make sure it is
working with any electrical Make sure the detergent is fresh and filled. The rinse agent makes the
appliance.. dry. Old, caked detergent will not water flow off the dishes faster, this
wash well. reduces spotting and aids drying.
NOTE: Check with the local water company concerning the water conditions in your area. With very hard water
more detergent may be required for good results. If you have soft water or a water softener, use less detergent.
7

6. Power Connections
Dishwashers plug into standard 120 volt wall receptacles with a three pronged (grounded) plug. If the dishwasher
fails to operate properly, the power cord may be preventing power from reaching the unit.
Most problems associated with the power cord or connection are caused by damage and/or loose connections
and will likely be visible.
CAUTION: To minimize the possibility of electric shock, be certain that the wall receptacle and circuit
are properly grounded before using the dishwasher. Use of a plug adapter to adapt to a two prong outlet is
NOT recommended. Under no circumstances should you attempt to cut off or otherwise remove the third
prong (ground prong) from the power cord..
PROCEDURE
Inspecting: Power Connections
Step 1: Be sure all dishwasher Step 2: Inspect power cord at Step 3: Pull plug from receptacle with
Controls are turned off connection to receptacle. Improper a firm quick tug. Always grasp the
connection could be the sole cause plug, never pull the cord. Be careful
of trouble. Not to contact the blades of plug.
Step 4: Inspect plug carefully for Step 5: To replace cord, disconnect remove
Damaged, corroded or loose terminals. mounting screws on power cord strain relief .
Look for signs of overheating around Disconnect internal connections and install
the molded portion. If plug is damaged new cord same as original. Reassemble
replace the power cord. dishwasher and check operation.
8

7. Removing Outer Casing7. Removing Outer Casing And Control PanelAnd Control Panel
PROCEDURE
Removing outer case
Step 1: For your personal safety Step 2:Remove stainless--steel screws Step 3:Open door and remove six
exercise caution when working with on both sides of outer casing. Screws on left and top edges of
any electrical appliance. inner liner.
Step 4: Remove casing screws on Step 5: Lift casing straight off Step 6: Remove six screws fastening
rear of unit front control cover.
9

8. Inner Wiring Connections Check
Power is carried to the components of the dishwasher by a network of insulated wires. These wires are connected to
the timer, switches and other dishwasher components by means of push-on connectors.
It is very important that the wiring be free of any damage. Any cut that reduces the diameter of the wire reduces
the amount of power it will carry. Also, the wire may overheat and eventually break at that point. If the terminals
become dull and oxidized they should be replaced.
Whenever servicing the wiring harness be sure to note the of any green and / or yellow/brown ground wires in the
area in which you are working. Be certain all are properly connected upon completion of service. This is vital to
avoid danger of shock or short circuit.
CAUTIONCAUTION: If replacement wire is required, use only appliance wire having the same temperature and guage rating
as the wire you are replacing. This information is usually printed on the wire itself.
PROCEDURE
Repairing wiring and connections
Step 1: Be sure all controls are Step 2: This procedure requires the Step 3: Inspect all push-on terminals
turned OFF. Disconnect power removal of the outer casing. If you and inner connecting wiring for signs
supply at distribution panel or are unfamiliar with this process, please of damage. i.e. burnt, pinched, loose or
unplug power cord from outlet. refer to procedure #7:Removing outer frayed.
Watch for sharp edges. Casing.
1010

9. Door Latch
The door latch is essential to the operation of the dishwasher. Latching the door closes a switch allowing electrical
current to flow to the timer. The timer controls all other components.
If the door latch switch is open, the dishwasher will not operate. The latch switch cannot be activated while the door
is open. This safety mechanism prevents the dishwasher from being operated when the door is open. However, if the
door latch switch contacts become stuck in the closed position, the dishwasher will not stop when door is opened during
the cycle.
PROCEDURE
Door Latch Switch Replacement
Step 1: Always unplug from Step 2: Remove outer casing. Step 3: Check for defects in micro-
receptacle before repairing. switch or connections. If switch is bad
remove the two mounting screws.
Disconnect and replace switch.
Step 4: Install new microswitch and
connect same as original installation.
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10.Timer
The dishwasher timer consists of a timer motor and a variety of switches that automatically controls every phase of the
dishwashers operation. The timer motor runs at a constant speed, like a clock. As it advances through the selected cycle,
the timer’s internal switches open and close in a precise sequence. When a preset period has elapsed, the timer opens the
switch again and shuts off the power to that component.
All outgoing wires from the timer are number-coded. By referring to the circuit diagram, you can trace the path of
electrical current from the timer to any component.
The timer is a very reliable mechanism. It is best to eliminate all other possible causes before attempting to test or
replace the timer.
PROCEDURE
Inspecting and replacing timer
Step 1: Be sure all controls are Step 2: This procedure requires the Step 3: To check timer motor, set the
turned OFF. Disconnect power removal of the outer casing. If you timer to the off position and check for
supply at distribution panel or are unfamiliar with this process, please continuity through the motor windings
unplug power cord from outlet. refer to procedure #7:Removing outer (approx. 2k ohms). If the windings are
Watch for sharp edges. Casing. open replace timer.
Step 4:Refer to dishwasher’s circuit
Diagram page 1 to see which contacts
close to activate a particular component.
(Example:4 to 4a close for drain pump)
Refer to the timing chart on page 14 to
determine when the individual contacts
close .
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FRONT OF UNIT

PROCEDURE
Inspecting and replacing timer (Continued)
Step 5:Remove the leads from the Step 6:To remove the timer, remove Step 7:Move leads terminal for
Terminals to be checked. Using an the two timer mounting screws. terminal to the new timer.
ohm meter, check the resistance
through the contact while turning the
timer. If the contacts being checked
do not close at the appropriate times
during the cycle, replace the timer
.
Step 8: Remount new timer Step 9: Reassemble dishwasher, apply
power and test operation.
13

Timer : Cam Timing Chart
14

11. Power switch and option switch
When you press the power switch on, and the dishwasher remains dead with no power light this may be a
malfunction of the power switch.
When you press the option switch and the heating element can not be energized and the Sani/Econo light does
not come on, this may be a malfunction of the option switch.
PROCEDURE
Inspecting / replacing : power switch and option switch
Step 1: Be sure all controls are Step 2: This procedure requires the Step 3: Using a ohm meter, check for
turned OFF. Disconnect power removal of the outer casing. If you bad contacts in the power or option
supply at distribution panel or are unfamiliar with this process, please switches.
unplug power cord from outlet. refer to procedure #7:Removing outer
watch for sharp edges. casing..
Step 4: If the switch is defective,
replace the switch and reconnect
same as original installation.
15

12.Water inlet valve
The water inlet valve controls the flow of water into the dishwasher. A solenoid coil attached to the valve housing
creates a magnetic field when energized. This magnetic field pulls open a plunger inside the valve allowing the water
to flow through and into the dishwasher.
The water fill is controlled by the timer, which opens the valve for a predetermined amount of time
Under normal conditions the tub should fill to approximately 85mm. or 3.5in. from the bottom of the sump. Open
the dishwasher after any fill cycle to check for normal water level.
A malfunctioning water inlet valve solenoid may only allow the dishwasher to fill intermittently. In this case no
water will enter the dishwasher during the rinse cycle. This problem can best be diagnosed by operating the dishwasher
and listing for the water entering during each fill cycle.
PROCEDURE
Inspecting and replacing : Water inlet valve
Step 1: Be sure all controls are Step 2: This procedure requires the Step 3: Locate valve where inlet hose
turned OFF. Disconnect power removal of the outer casing. If you is attached. Check wires and valve
supply at distribution panel or are unfamiliar with this process, please. body.
unplug power cord from outlet. refer to procedure #7:Removing outer
watch for sharp edges. casing..
Step 4: If water fill is less than Step 5: Using a ohm meter check for Step 6: To replace water valve,
normal,detach fill hose to expose continuity through the solenoid. If shut off water supply and disconnect
filter screen. Clean or replace as solenoid winding is open, replace faucet coupling.
necessary. valve.
16

PROCEDURE
Inspecting and replacing: Water inlet valve (continued)
Step 7: Disconnect incomming water Step 8: Remove mounting screw that
Water supply hose. Remove clamp secures fill valve to rear panel. Install
and detach smaller hose running into new valve and reconnect leads and
dishwasher tub. water lines. Reassemble dishwasher
and reconnect water and power supply.
NOTE: If water continues to fill, even when power is disconnected, this is caused by damage to, or sediments
in valve housing or bellows. In either case entire valve should be replaced.
NOTE: If open winding in solenoid were proceeded by continuous filling and draining. Make sure timer is
Advancing through the fill cycle. Continuous duty will burn out water valve solenoid.
17

13. Pressure Switches
There are two pressure switches on the dishwasher. One is for controlling normal water level set at approx. 85mm
or 3.5 inches of water in sump. This will be referred to as the Normal Pressure Switch. The other one is for
preventing overflow and is set for approx. 102mm or 4 inches of water in sump. This one will be referred to as the
Safety Pressure Switch. If the water in the tank rises above the pre-set level, the safety pressure switch opens the
Circuit and stops power to the fill valve and closes the circuit to the drain pump, expelling excess water.
The safety pressure switch shuts water off only in cases of electrical malfunction. If a mechanical defect or foreign
object causes the inlet valve to stick open, the safety pressure switch will not be able to stop the overflow.
The safety pressure switch should never cut off the water inlet valve solenoid during normal fill, if it does it is not
properly adjusted.
PROCEDURE
Inspecting and replacing: Pressure switch
Step 1: Be sure all controls are Step 2: This procedure requires the Step 3: Hold a ruler vertically in the
turned OFF. Disconnect power removal of the outer casing. If you sump, the tub should fill between
supply at distribution panel or are unfamiliar with this process, please. 81-87mm or 3.25 to3.5 inches.
unplug power cord from outlet. refer to procedure #7:Removing outer
watch for sharp edges. casing..
Step 4: If the water level is incorrect Step 5: If a pressure switch is bad Step 6: Pressure switches must be
Check the pressure switch connecting remove mounting screw and replace adjusted with a special screwdriver
hoses and all connections to see if switch. to the proper level (step 3).
there is air leakage and pressure loss. After adjustment is complete a drop
Reseal any loose connections. of glue should be placed on the
Threads to prevent further movement
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