Mechanical Dishwasher

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A dishwasher combines water with detergent. It heats the mixture and sprays it against the dishes. It pumps out the dirty water and then rinses the dishes with clean water mixed with a rinsing agent. After pumping out the rinse water, the dishes are dried by either heat or air drying. The selector switch allows you to pick a variety of cycles which vary the length of wash, water temperature and drying temperature. When the door latch is closed, the door switch is engaged which allows the dishwasher to operate. Based upon the chosen cycle, the selector switch signals the various components to operate at the appropriate stage of the cycle. The timer regulates the length of each stage of a cycle. The water inlet valve fills the tub with water; a float in the tub prevents the dishwasher from overfilling. Either the float or the timer signals the inlet valve to close. The detergent is then released into the tub. In many dishwashers the mixture is heated with an electric heating element. Water that is not warm enough results in poor cleansing.

The motor turns a pump which forces the water up through the spray arms and spray tower (if any). The pressure of the water causes the arms to turn. Some dishwashers have a two-way motor. When it turns in one direction, it pumps the water through the spray arms. When it turns the other way, it pumps the water out through the drain. If the motor only turns in one direction, then an actuator moves to channel the water either to the spray arms or to the drain. After the detergent cycle is complete the dishes are rinsed. If the dishwasher has a rinse agent feature, the rinse agent is added to the rinse water. Once the rinse cycle is completed and the water has been pumped out, the dishes are dried. An electric heating element heats the interior of the dishwasher. Some dishwashers also have a fan to circulate the air. A thermostat prevents the dishwasher from overheating. Some dishwashers employ soil sensors to monitor the clarity of the wash water. When the water becomes clear, the sensor signals the control timer to advance to the next cycle.

 

TROUBLESHOOTING GUIDE

DISHWASHER DOES NOT WORK – NO SOUND, NO WATER, NO LIGHTS

Check for a blown fuse or tripped circuit breaker

Check that the dishwasher is plugged in

Inspect the wiring connection to the dishwasher for burns or breaks

Check the door latch

Test the door switch

Test the selector switch

Test the motor start relay

Test the motor

 

DISHWASHER DOES NOT START, AND THE MOTOR HUMS

Un-jam the motor

Test the motor

Test the motor start relay

Check the drive belt

 

DISHWASHER DOES NOT FILL

Check that the water supply is turned on; the valve may be located under the sink.

Check the door latch

Test the door switch

Inspect the float assembly

Inspect the fill tube for kinks

Test the float switch

Check the inlet valve filter screen

Test the water inlet valve

Test the drain valve lever arm

Check the drain valve

 

WATER DOES NOT DRAIN FROM THE DISHWASHER

Check sink, drain and drain hose for restrictions

Un-jam the motor

Un-jam the pump

Check the drain valve

Check the drive belt

If you have a brand new dishwasher or garbage disposal, check the knock out plug on the garbage disposal

 

DRY CYCLE PROBLEMS

Test the heating element

Test the drying fan

Test the thermostat

 

DISHWASHER DOES NOT COMPLETE CYCLE

Test the thermostat

Test the heating element

 

DETERGENT CUP DOES NOT OPEN

Check the detergent cup for obstructions

Test the actuator arm

Test the bimetal assembly

 

CYCLE TIMES ARE TOO LONG

Test the heating element

Test the thermostat

 

DISHES ARE NOT CLEANED ADEQUATELY

Check for adequate water level

Check the spray arms and spray tower

Check the water temperature

Check the detergent cup

Check the inlet filter screens

Check the water pressure

Test the water inlet valve

Check the drain valve

Test the selector switch

Test the heating element

Test the bimetal terminal assembly

WARNING: disconnect power before removing any parts from the oven. If you are not comfortable doing any of these tests yourself, than you should get a technician to check the appliance for you.

The information in this website contains POSSIBLE REPAIR SOLUTIONS. This information is intended to assist customers in troubleshooting the possible problems that your appliance might be having. The information comes from a variety of sources and therefore in no way implies or suggests that this will be a guaranteed solution for your problem. They are merely a guide to help to assist you in troubleshooting your appliance. Any parts that are purchased in the effort to fix your appliance, that do not solve your problem are the sole responsibility of the consumer. Timers that are repaired or purchased from Turner’s Timer Repair are NOT RETURNABLE and our normal warranty policy will take effect.