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The dishwasher combines water pressure, detergent and heat to clean dishes and kitchen utensils more thoroughly and efficiently than hand washing. Although a dishwasher is a complex machine, its most common problems are usually due to simple failures that are easy to fix. During a typical 75-minute cycle, the dishwasher tub fills with water, which mixes with detergent released by the deter gent dispenser. The detergent-and-water solution is then warmed to about 150°F by the heating element and pumped through the spray tower and spray arm, which spins about 40 times a minute, hurling the mixture against the dishes and washing away even hardened food waste. After the dishes are rinsed and the dishwasher drained, the air inside the machine is warmed by the heating element, drying the dishes. (Some newer models have an energy-saver feature that turns off the heating element during the drying cycle, using a small blow to air-dry the dishes.) Built-in dishwashers are installed under a kitchen counter with permanent plumbing and wiring connections. Portable models have a plastic coupler so that they can be connected to the sink faucet and drain, casters that allow them to be rolled t and from the sink, and a power cord that plugs into a grounded 120-volt outlet. === BUILT-IN DISHWASHER Rinse agent dispenser Operates during the final rinse. Lower spray arm May be made of steel or plastic, and may sit atop a filter screen that catches small food particles. Some washers have two or three spray arms on different levels. Older models may have an impeller instead. Heating element Maintains water temperature and usually provides heat drying. Some models also have a blower heater within an air duct for the DRY cycle, or an energy-saver feature that turns off the heating element during the drying cycle: Pump and-motor assembly On most models the motor is mounted at a right angle to the spray arm. Selector switch Alters operation of timer to provide a choice of long or short wash cycles. Door switch Prevents dishwasher from running when door is open. Cycle extender switch Usually operates a POTS AND PANS cycle, an extra feature on some models. Float switch Protects against water overfill. A few older models use a pressure switch instead, mounted inside or under the tub. === The most common dishwasher problem is incomplete cleaning. Before repairing the appliance itself, check for other possible causes: improper loading, low water temperature, low water pressure, and ineffective detergent. Always rinse dishes, pots and pans in the sink before loading. Large pieces of food can clog filters and small, hard objects such as olive pits can dam age the plumbing. Read the dishwasher's Use and Care manual for directions about arranging dishes in the machine, Water temperature is critical. For clean dishes, the water must be between 140°F and 160°F; a lower temperature won't dissolve grease or detergent. The water pressure to the dishwasher must be adequate, too. If pressure is too low, run the dishwasher only when no water is being used elsewhere in the house. Your use of detergent can also affect how well your dishes come clean. Avoid using old dishwashing detergent; it can become ineffective in as little as two weeks after the foil seal is broken. If the water in your area is hard-high in mineral content- you may need to use more detergent. If you have soft water, or use a water softener, you may need to use less deter- gent. Your machine may also have a rinse agent dispenser; be sure it’s filled. A rinse agent makes water flow off dishes faster than normal, reducing water spotting. The most difficult dishwasher repair involves servicing the pump and motor. An improperly installed pump seal, For example, can cause a leak into the motor, severely damaging the dishwasher. Therefore, only simple testing and removal of the pump-and-motor assembly has been shown (84). If you find that the pump or motor is faulty, either remove the entire assembly and take it for repair, replace it with a new assembly, or call for professional service. When repairing a dishwasher, always turn off the power at the house's main service panel or, for portable models, unplug the machine. TROUBLESHOOTING GUIDE
ACCESS THROUGH THE CONTROL PANEL 1 Unscrewing the control panel. Turn off power to the dishwasher. Remove the control panel retaining screws located, in most cases, inside the dishwasher door. Hold the control panel to keep it from falling. 2. Freeing the control panel. Close the dishwasher door. Supporting the panel to avoid damaging wires, lower it away from the door, as shown. (On some machines, you may first have to remove the door handle or door panel.) You now have access to the selector switch, cycle extender switch, door switch and timer. ACCESS THROUGH THE DOOR PANEL 1. Removing the door panel. Turn off power to the dishwasher. Open the door and, keeping one hand underneath it to support the panel, remove the retaining screws (above, top) and lower the panel away (above, bottom). On some dishwashers the screws are hidden under metal strips; lift the strip to reach the screws. 2. Getting to the door panel parts. With the control panel and door panel removed, you now have access to the door switch, detergent and rinse agent dispensers, and the wiring diagram. ACCESS THROUGH THE LOWER PANEL 1 Removing the lower panel. Turn off power to the dishwasher. Depending on the model, remove any retaining screws (inset) and, to free the panel, pull it down or lift it off hooks (above). 2 Getting to parts under the tub. With the lower panel removed, you have access to the water inlet valve, heating element terminals, pump-and-motor assembly and drain valve sole noid. Some of these parts are hard to reach, so for complicated repairs on a built-in model, pull the machine free from the counter and tilt it on its back (below). FREEING AND TILTING THE MACHINE 1 Disconnecting the power and water supply. Turn off the water and power supply at their sources. Open the door and remove the screws that secure the top of the dishwasher to the kitchen counter. Remove the lower panel (step 1, above), then turn the threaded leveling feet to lower the dishwasher slightly. Keeping a shallow pan handy to catch dripping water, use a wrench to disconnect the water supply line from the water inlet valve (above). Disconnect the drain hose from the sink drain. Unscrew the cover of the power cord junction box, near floor level, and disconnect the power cord. 2 Tilting the dishwasher. Slide a blanket beneath the machine to protect the floor from scratches, then rock the appliance clear of the cabinet. Make sure you have a steady grip on the machine, and with your legs bent, gently lower it backward (above). SERVICING THE SELECTOR SWITCH 1. Testing the selector switch. After turning off the power or unplugging the power cord, remove the control panel (73) and inspect the selector switch. Repair any loose or broken wires (136). Refer to the wiring diagram to test each pair of switch terminals for continuity, using a continuity tester or a multitester set at RX1 (above). To make sure you reconnect the wires properly, disconnect only two at a time, reconnecting them before moving on to the next set. If any pair of terminals fails to show continuity with the appropriate switch button pressed, remove and replace the switch. 2. Replacing the selector switch. Detach the selector switch bracket from the control panel by removing the mounting screws and lifting the bracket from the control panel (above). Pull the buttons off, keeping them in order for reinstallation. Unscrew the faulty switch from its bracket, leaving the wires attached. Install a new switch and replace the pushbuttons. Finally, transfer the wires one by one from the old switch to the same terminals on the new switch. Replace the bracket in the control panel. SERVICING THE CYCLE EXTENDER SWITCH 1 Testing the cycle extender switch. Turn off power to the dish washer, remove the control panel (73) and inspect the switch. Repair any loose or broken wires (136). Disconnect the wires from the switch terminals and label their positions. With a multitester set at RX1, test terminals H2 and L2 for continuity, as shown. Then set the multi-test at RX100 and test terminals H2 and Hi; they should show resistance. If the switch is faulty, replace it. 2. Replacing the cycle extender switch. Depending on your model, unscrew (above) or unclip the switch from the control panel. Install a new switch, reconnecting the wires one by one to the new terminals, and reinstall the control panel. SERVICING THE TIMER 1 Testing the timer motor. After turning off the power or unplugging the power cord, remove the control panel (73). Disconnect the timer motor wires and, using a multitester set at RX100, test the timer motor terminals (above); they should show partial resistance. If the motor is faulty, replace the entire timer (step 4). If not, next check the timer plug and terminals. 2 Disconnecting the timer plug. Keeping a solid grip on the timer plug, wiggle it away from the timer (above). Once it’s removed, inspect the plug (inset) for loose contacts. If any contacts protrude from the plug, push them back into place. 3 Testing the timer terminals. For this step, refer to the dish washer's wiring diagram and timer chart, found inside the door panel (73) or available from the manufacturer. Use the wiring diagram to identify the pairs of terminals that control the faulty cycle. Disconnect the wires from those terminals and test each pair for continuity with a multi-tester set at RX1 (above). Turn the timer dial slowly through the full cycle. The timer chart will show at which points in the cycle there should be continuity. To make sure the wires are properly reconnected, replace each pair before disconnecting another pair. If any pair of terminals does not show continuity, replace the timer. 4 Replacing the timer. Pull off the timer dial by hand, then remove the timer mounting screws (above). Disconnect all other wires, including the motor wires, and mark them with masking tape for reassembly. Install a new timer, reconnect the wires and rein stall the timer plug. Replace the dial and the control panel. SERVICING THE DOOR SWITCH 1 Testing the door switch. Before testing the door switch, check to see if the door catch closes securely. On many models, the catch can be tightened or repositioned by loosening the retaining screws, sliding the catch in or out, then retightening the screws. Other wise, shut off the power and remove the control panel (73). With the door closed and locked, disconnect the wires from the door switch terminals and test for continuity using a multitester set at RX1 (above). If there is no continuity, replace the switch. 2. Replacing the door switch. With the wires disconnected, remove the door switch retaining screws (above), install a new switch and reconnect the wires. REPLACING THE DOOR SPRINGS Replacing springs on built-in models. After turning off the power supply, locate the door springs. They are usually on the sides of the machine, under the front corners of the tub, so pull the dishwasher out from the counter (74). If the springs are weak or broken, remove the ends from their holes by hand and replace them as shown. For proper tension, always replace door springs in pairs, even if only one is broken. If your dishwasher has a series of holes next to the pair on which the springs are hooked, you can adjust the tension by hooking each spring into a different hole. Replacing springs on portable models. After unplugging the machine, remove the side panels by unscrewing the retaining screws that secure them to the frame. The springs are attached to an anti-tip mechanism that prevents the machine from falling forward when the door is opened and the racks pulled out. If the springs are weak or broken, replace them by hooking new springs into position (above). For proper tension, always replace springs in pairs, even if only one is broken. REPLACING THE DOOR GASKET Inspecting and replacing the door gasket. Turn off power to the dishwasher. Open the dishwasher door, remove the dish racks and inspect the door gasket. If it’s cracked or otherwise damaged, replace it with an identical gasket. Some may also have a tub gasket for extra protection; check this, too. On some dishwashers, the gasket has clips or tabs that can be pried out with a screw- driver (left). Other gaskets are secured with retaining screws. If the replacement gasket is kinked, soak it in warm water for a few minutes before installation. If the gasket slides into a track, lubricate the gasket with soapy water or silicone to make installation easier. (Don’t use oil or grease.) Press the center of the gasket into the top center of the door. Continue around the door, pressing into place several inches at a time. Secure the ends with the original clips or brackets. If the gasket is good, check to see if the door catch closes securely. On many models, the catch can be tightened or repositioned by loosening the retaining screws, sliding the catch in or out, then retightening the screws. CHECKING THE DETERGENT AND RINSE AGENT DISPENSERS Inspecting the detergent dispenser. Although their design may differ, all detergent dispensers operate in much the same way. The dispenser is opened mechanically by the timer at a predetermined point during the cycle. Breakdowns, usually due to a damaged part, are infrequent. First turn off the power or unplug the dishwasher, then check the deter gent cup inside the door for caked detergent; clean it if necessary. Also check the 0-ring or gasket, if any, inside the cup's cover, and replace it if damaged. If your model has a movable cup, open and close it by hand to see if it’s stuck. Next remove the door panel (73) and check the spring-and-lever mechanism for stuck or broken parts (above). Replace any part that is damaged. Inspecting the rinse agent dispenser. If your dishwasher has a rinse agent dispenser, the rinse agent is released either by an arm on the detergent dispenser or by the timer. First turn off the power to the dish- washer and remove the door panel (73). Make sure the fill cap is tight and inspect the rinse agent dispenser for signs of damage. If it’s split or cracked, replace it. If your model resembles the one shown above, remove the wires to the bimetal terminals and test the terminals for continuity, as shown. If there is no continuity, replace the bimetal assembly. If the dispenser leaks, check the washers or gaskets and replace them if cracked or brittle. UNCLOGGING THE AIR GAP (Built-in models) 1 Access to the air gap. This plumbing part, required by many local building codes, prevents water in the kitchen sink or garbage disposer from backing up into the dishwasher. Pull the cover off the air gap, located next to the sink faucet, and unscrew the cap under the cover, as shown. (On portable models, the faucet aerator serves as an air gap, since the sink faucet is higher than the dish washer.) 2. Cleaning the air gap. With tweezers, remove any debris such as glass, bones or toothpicks from the small tube in the center of the air gap (above). Rinse the cover and cap and reassemble. INSPECTING AND REPLACING THE DRAIN HOSE 1. Inspecting the drain hose. Turn off the power and water supply to the dishwasher. Remove the lower panel (74) and inspect the drain hose for kinks, cracks or splits, Begin at the pump, straightening any kinks by hand (above, left). If the kink remains, replace the hose. Also check that the hose clamp is secure; if not, reposition it with pliers, If you don't find the problem under the dishwasher, follow the hose to the kitchen sink drain or garbage disposer (built-in models, above, right) or the faucet coupler (portable models). This means gaining access to the side of the dishwasher, so pull a built-in model away from the counter (74) or remove the side and top panels of a portable model (77). If the hose is collapsed, kinked, or cracked, replace it. 2. Replacing the drain hose. With a shallow pan handy to catch dripping water, disconnect the hose from the pump by squeezing the spring clamp with pliers (above). Then disconnect the hose under the kitchen sink drain (built-in models) or faucet coupler (portable models). Position the new hose and reconnect it at both ends with new clamps. SERVICING THE SPRAY ARM 1 Checking for obstructions. Turn off power to the dishwasher and slide out the lower dish rack. Rotate the spray arm to see if it moves freely (above); the ends of the arm should also move up and down slightly. If bent or damaged, replace the spray arm. 2 Removing the spray tower. If your model has a spray tower in addition to the spray arm, pull the telescoping parts to see if they move freely. Unscrew the tower by hand and remove it, as shown. Check for clogs and clean if necessary. 3 Removing and replacing the spray arm. Remove the spray arm by unscrewing it, as shown, or by removing a plastic ca p. Keeping them in order, lift out the spray arm and its washers, gaskets, or bearings. Clean or, if it’s bent or damaged, replace the spray arm. If your model has a strainer below the spray arm, remove it and clean with an old toothbrush under running water. 4 Cleaning the spray arm. Check the spray arm for foreign objects. Using a stiff wire bent at a right angle at the tip, unclog the holes (above). If your model has a second spray arm mounted above the first, clean it, too. Then rinse the spray arm, tower and strainer under running water and reassemble the parts. MEASURING THE WATER TEMPERATURE Measuring the water temperature. Turn on the dishwasher, then interrupt it during the first wash cycle by opening the door. Steam will pour out, but the water will remain in the bottom of the tub. Place a candy or meat thermometer in the water, as shown. It should read at least 140°F. If not, raise the tempera ture slightly at your water heater thermostat and test again after one hour. If your water heater is already set to a higher temperature than is being delivered to the dishwasher, keep in mind that a loss of one degree per foot of pipe is normal. If the water temperature in the dishwasher continues to stay below 140°F, check the heating element (below). SERVICING THE HEATING ELEMENT 1. Testing the heating element. Turn off power to the dishwasher and remove the lower access panel (74). Disconnect the heating element terminal wires, located under the tub, and test the terminals for continuity, using a multitester set at RX1 (above). The tester should indicate partial resistance. If not, replace the element. If the test shows continuity, check the element for a ground. Pull one of the rubber covers to the end of the terminal. Touch one probe of the tester to the metal sheath and the other to a terminal (inset). A continuity reading means the heating element should be replaced. 2. Replacing the heating element. Slide off the rubber terminal covers and remove the locknuts that hold the element in place under the tub (top). Then, from inside the tub, remove the element from its bracket (bottom). Lift the element from the tub and install the exact replacement for your make and model. Reconnect the wires to the terminals. CHECKING THE WATER PRESSURE Checking the water pressure. Turn on the dishwasher and let it run until the dial reaches the first wash cycle. Then stop the machine by opening the door. Steam will pour out, but the water will remain in the bottom of the tub. Let the water cool, then bail it out (left) into a gallon container-emptying it into the sink as it becomes full. Remove the s arm (80) if it’s in your way. If there is less than 2 1/2 gallons (2 imperial gallons) of water in your dishwasher, the water pressure is probably too low. To remedy the problem, avoid using the house water supply while the dishwasher is in use. REPAIRING THE FLOAT SWITCH 1. Inspecting the float. Turn off power to the dishwasher. Open the dishwasher door, remove the lower dish rack and jiggle the float up and down to check that it moves freely. Then pull it out and look for obstructions (above). On some models, the float is held in place by a clip under the tub. Remove the lower panel (74) and remove the clip. On other models, the float is hidden by a cover that first must be removed. Replace the float with a new one if it’s dam aged. If the float moves freely but the machine either doesn't fill or overflows, test the float switch. 2. Testing the float switch. Remove the lower panel (74) and detach the wires from the float switch terminals. Put the switch in the ON position by pulling down on the lever, and the terminals for continuity. If there is no continuity, remove the switch by unscrewing it from its mounting bracket and replace it. REPAIRING THE WATER INLET VALVE 1. Inspecting the water inlet valve solenoid. Turn off the power and water supply to the dishwasher. Remove the lower panel (74); you may also pull out the machine and tip it back for easier access. (On some portable models, remove the top of the machine to locate the water inlet valve.) If your machine leaks, make sure the incoming water line and the hose that connects the inlet valve to the tub are securely fastened. Tighten, if necessary, using an adjustable wrench or hose-clamp pliers. If you suspect the valve is faulty, remove the wires from the inlet valve solenoid terminals and test for continuity with a multitester set at RX1, as shown. If there is no continuity, remove and service the valve. 2. Servicing the water inlet valve. With a shallow pan handy to catch dripping water, use hose-clamp pliers to remove the hose that connects the inlet valve to the tub, as shown. Then use a wrench to disconnect the incoming water line. To free the water inlet valve, remove any screws that secure the valve bracket to the tub. If the valve is cracked or otherwise damaged, replace it. Using a small screwdriver, pry out the water inlet valve screen (inset). If it’s a plastic screen, rinse it and clean it with an old tooth brush, then replace it in the valve. If the screen is metal, it won't retain its shape; replace it with a new one. Reinstall the valve, water line and hose and check all connections.
REPAIRING THE DRAIN VALVE
1. Locating the drain valve. Drain valves are used in dish washers with non-reversible motors. Turn off power to the dish washer and remove the lower panel (74). Count the number of wires attached to the motor. A motor with two or three wires is non-reversible, as above; one with four wires is reversible. 2. Checking the gate-arm mechanism. Tilt the machine on its back (74) to make it easier to reach the drain valve. If your drain valve has a gate-arm mechanism, move it by hand (above); it should move freely up and down. There should be two springs; replace any that are broken or missing. 3 Testing the drain valve solenoid. Disconnect the wires from the drain valve solenoid terminals and, using a multitester set at RX1, test it for continuity (above); the solenoid should show partial resistance. If there is no continuity, replace the solenoid. 4 Replacing the drain valve solenoid. Noting carefully how they are attached, remove the mounting screws (above) and detach the solenoid springs and wires. Install a new solenoid and reattach the wires. SERVICING THE PUMP-AND-MOTOR ASSEMBLY 1. Inspecting the motor fan blades. Turn off power to the dishwasher and remove the lower access panel (74). If it’s a built-in model, pull the dish washer away from the cabinet and tilt it on its back (74) for access to the pump-arid- motor assembly. If the motor fan blades are visible on your model, turn them by hand (left); they should move freely. If not, the pump seal may be stuck or an object may be lodged in the assembly. Check for obstructions; if none are visible, remove the assembly or call for professional service. 2 Testing the motor. Snap off any protective brackets and disconnect the motor wires from the motor terminals. Test for continuity (far left); with the multi- tester set at RX1, the motor should show partial resistance. If there is no continuity, replace the pump-and-motor assembly or call for service. If the motor shows continuity, test next for a ground. Place one probe of the multitester on the bare metal motor housing, the other probe on each terminal in turn (near left). A continuity reading indicates a ground; replace the pump-and-motor assembly or call for service. 3 Disconnecting the pump-and-motor assembly. With a shallow pan handy to catch dripping water, use hose- clamp pliers to disconnect the hoses from the pump (far left). Mark the hose positions for reconnection. Detach the drain valve solenoid wires, then unscrew the clamp closest to the pump on each boot connector (near left). 4 Replacing the pump-and-motor assembly. Remove the ground wire from the assembly and, on models with access under the tub, pull the assembly free from its hanger (far left). On other models, remove the assembly from inside the tub (near left). You now have access to the pump. Although there may be pump repair kits available for your model, attempt such a repair only if you are a highly experienced do-it-yourselfer. Otherwise, replace the entire assembly or take it to a service center for repair. Prev: GAS RANGES Next: GARBAGE DISPOSERS Home top of page |