Repairing a Dishwasher

Appliances

Do you find the control panels on dishwashers intimidating? Don’t worry, they’re not as complicated as they seem. While the control panel may be tricky, dishwashers themselves haven’t changed much in the last twenty years. This means that you can easily repair most malfunctions yourself. In this article, we’ll provide some tips for DIY service and maintenance.

You may be able to replace dishwasher parts as a unit, which can be less expensive and easier than calling a professional. If you’re not sure whether a part is still usable, take it to a professional for testing. Once you have the repair estimate, you can then decide whether to buy a new part or have the old one repaired.

Dishwashers typically run on 115-120 volt power and use water directly from the water heater. Wastewater is drained into the sink’s drainpipe. It’s important to set the temperature control of the water heater to no less than 140 degrees Fahrenheit for the best dishwashing results. Unless your dishwasher is a newer model that preheats incoming water, cooler water won’t get your dishes clean. The water shutoff for the dishwasher is usually located below the sink.

It’s important to be cautious when working on dishwashers because they’re connected to both the plumbing and electrical systems. Before doing any work, unplug the unit or turn off the power to it. Remove the fuse or trip the circuit breaker that controls the circuit at the main entrance panel or a separate panel. Shut off the water supply in the basement or crawl space under the kitchen.

Basic Dishwasher Operating Checks

The control panels on dishwashers may look complex, but they’re not difficult to repair. Learn how to repair your dishwasher.

If your dishwasher isn’t working, start by making these operating checks:

Step 1: Check to make sure the unit is receiving power. If it plugs into a wall outlet, check the cord, plug, and outlet to ensure they’re functioning properly. Also, make sure the switch controlling the outlet is turned on. Most built-in dishwashers are wired directly into a circuit, so check the main entrance panel for a blown fuse or tripped circuit breaker and restore the circuit. If your home is older, the dishwasher may be wired to a separate entrance panel. In this case, look for a blown fuse or breaker at this panel and restore the circuit.

Step 2: If the circuit is receiving power and the wall outlet is controlled by a switch, the switch may be faulty. Test the switch with a voltage tester. Remove the switch cover plate and place one probe of the tester on one terminal and the other probe on the other terminal. If the tester bulb lights up, the switch is functioning. If it doesn’t, the switch is faulty and needs to be replaced with a new one of the same type.

Step 3: Ensure Proper Door Closure

Make sure that the dishwasher door is tightly closed and latched. The machine will not function if the latch is not properly engaged. To check the latch, close and latch the door while holding the latch tightly in place. Then, still pressing the latch closed, turn the control knob to the ON position. If the dishwasher starts working, the latch is faulty and needs to be cleaned, tightened, or replaced.

Step 4: Check Water Supply

Make sure that the water is turned on and the temperature is high enough. A breakdown in the water heater could stop the flow of water to the dishwasher. Test the hot water in the kitchen sink or bathroom. If you can draw hot water, the water heater may not be at fault.

Step 5: Verify Control Panel Settings

Make sure that the controls on the control panel are properly set. The newer push-button controls can be very sensitive, so ensure that the buttons are firmly pressed into position.

If you have gone through these five checks without finding a solution, it’s time to delve deeper into the dishwasher.

Disassembling the Dishwasher

Most dishwashers’ working parts can be accessed through the front door of the unit. Many repairs can be made by opening the door and reaching into the various component parts, such as the sprayers, strainers, float switch, racks, and door latch.

To get to the control panel on the door, remove a series of retaining screws around the panel. These screws may be under molding trim strips, which usually snap onto the metal housing. Pry off the strips with a stiff-bladed putty knife or a screwdriver, or remove a setscrew that holds the molding. The control knobs are friction-fit on shafts or are held by small setscrews in the base of the knobs. In some dishwashers, the entire front door panel must be removed to gain access to the control components. This panel is held to the door by a series of retaining screws, usually found around the edge on the inside back of the door.

On many models, once the control panel is removed, the door panel can be removed by unscrewing a series of fasteners holding the door panel in place. Sometimes these retaining screws are covered by trim moldings, which must be pried or slipped off. For access to the motor, pump, hoses, inlet valves, and other parts, remove the lower access panel. This can usually be done without removing the entire door. The panel may be held by retaining screws, or it may lift up and off metal hangers.

If the dishwasher is portable, tip the machine over on its back or side before removing the control door or lower access panels. This may give you a more comfortable working position.

Once you can get inside the dishwasher, knowing the major parts and how they function will help you assess the problem. We’ll review the main parts and how to check them in the next section.

Repairing the Door and Switches

©2006 Publications International, Ltd. For repairs to the timer, door latch, or switches, remove the control panel. To take it off, remove a series of retaining screws and the control knobs, and lift off the panel.

When your dishwasher isn’t working properly, you should check several main components, such as the door gasket, door latch, switches, and timer.

Replacing the Dishwasher Door Seal

If water is leaking from the dishwasher door, the door seal may need to be replaced. Inspect the seal by opening the door and checking if it is soft and flexible. If it appears worn, cracked, or stiff, it should be replaced.

Once the new seal is in place, check that it fits tightly against the door frame with no gaps or bulges. If needed, adjust the retaining screws or refit the seal clips or channel. Run a wash cycle and check for leaks.

If there is still a leak and the seal is properly fitted, try adjusting the door latch. The goal is to position the seal against the frame without flattening or squeezing it too much when the door is closed. Make adjustments to the latch or seal until it fits snugly against the frame.

Servicing the Dishwasher Door Latch

The door latch on a dishwasher can experience wear and tear from repeated use, leading to mechanical issues. A loose or misaligned latch can cause the door to not close properly, preventing the dishwasher from starting.

To fix this, try adjusting the position of the latch by loosening the screws and sliding it with pliers or fingers. Test the alignment by opening and closing the door and tighten the screws once it is correctly positioned.

If the dishwasher still doesn’t start after adjusting the latch, it may need to be replaced. Install a new latch the same way the old one was connected, and test it by opening and closing the door and turning the control knob to the on position.

Servicing the Dishwasher Door Switch

Many dishwashers use a switch that is activated by the door latch to start the machine. If the latch is not properly engaged or the switch is faulty, the dishwasher will not operate.

To test and repair the switch, first latch the door and hold it tightly closed. Turn the control to the on position. If the dishwasher starts, the lock unit may need to be adjusted. If adjusting the lock unit doesn’t work, use a volt-ohm-milliammeter (VOM) to test the switch. Remove the panel covering the switch and clip the VOM probes to each terminal. If the meter reads zero, the switch is working. If it reads higher than zero, the switch needs to be replaced.

Install a new switch of the same type and connect it the same way the old one was connected.

How to Maintain the Float Switch

A float switch is responsible for preventing dishwashers from overfilling. It can be found at the bottom of the unit. Here is a guide on how to check and replace it:

Step 1: Open the door and remove the bottom dish rack. Check if the float valve is stuck. If it is, remove any food debris around it and tap the top of the float with the handle of a screwdriver to loosen it.

Step 2: If tapping doesn’t work, remove the lower access panel and find the float and float switch. Test the float switch with a VOM set to the RX1 scale. Unscrew one electrical lead wire from the switch terminal and clip one probe of the VOM to each terminal. A zero reading on the meter indicates that the switch is not faulty, but the problem may be the timer. A reading higher than zero indicates a faulty switch.

Step 3: Replace the switch with a new one that fits the dishwasher. The switch is held by screws to a mounting bracket, so remove them to take out the old switch.

Step 4: Connect the new switch in the same way as the old one was connected.

Repairing Timer and Control Switches

Since the timer controls several operations, a flawed timer can cause several issues. The timer is a complex component, so it’s best not to attempt a DIY repair. Use a VOM set to the RX1 scale to test the timer. Remove the front control panel to access the timer, which is located directly behind the main timer control knob. Disconnect one of the timer’s terminal wires and clip one probe of the VOM to each terminal. A zero reading on the meter indicates that the timer is working fine, while a reading higher than zero indicates a faulty timer that needs replacement.

Attempt to test the selector and cycle switches using the same procedure. However, the wiring hookup may be too complicated to figure out on these switches. If you’re not confident you can handle these switches, call a professional service person. Replace a faulty timer or control switch with a new one made for your dishwasher.

The timer is linked to several wires that supply power to operate the various functions of the dishwasher. To replace the timer, have someone hold the new timer next to the old one. Connect the wires of the new timer one by one, removing the old wire and connecting the new one to ensure that you connect the wires correctly. The wires may be friction-fit on the terminals, so use long-nosed pliers to remove them. Don’t pull up on the wires, or you may break the connection between the wires and the clips.

After connecting the wires, position the new timer, secure it the same way as the old one, and replace the control panel and knobs.

If your dishwasher isn’t filling up with water correctly or isn’t drying the dishes, you most likely have a valve or heating element issue. The next section will discuss how to evaluate these types of problems.

Repairs for Valves, Dispensers, and Dish Racks

Checking and maintaining the various valves, detergent dispenser, and dish rack can ensure that the right amount of water and cleaner are working effectively in your dishwasher.

Maintenance of the Water Inlet Valve

The dishwasher’s water inlet valve regulates the amount of water that flows into the appliance. It can be activated by the timer or a solenoid. If the dishwasher fails to fill with water, follow these steps:

Step 1: Check that the water supply is turned on and there are no problems with the water heater. If the water heater is shut down, it will affect the water supply to the dishwasher.

Step 2: Verify that the timer is functioning correctly and running through its programmed sequences. If both the water supply and the timer are working correctly, the issue is likely with the inlet valve.

Step 3: Inspect the inlet valve located under the dishwasher’s tub. Malfunctions can occur when the screen inside the valve is blocked with mineral deposits. To solve this problem, remove the screen with a screwdriver and rinse it thoroughly with running water. Replace the screen afterward.

Step 4: If the valve is controlled by a solenoid, it will typically be connected to the side of the dishwasher. Use a screwdriver’s handle to gently tap both the solenoid and valve to free them from any obstruction. Then restart the dishwasher.

Step 5: If the dishwasher still won’t fill, test the solenoid with a volt-ohm-milliammeter (VOM) set to the RX1 scale. Disconnect one electrical lead to the solenoid and clip one probe of the VOM to each solenoid terminal. If the meter reads from about 100 ohms to 1,000 ohms, the solenoid is working correctly. If the reading is higher than 1,000, the solenoid is faulty and needs replacing.

Step 6: If necessary, replace the solenoid with a new one of the same size and type. Connect the new solenoid the same way the old one was connected.

If the inlet valve is worn or misshapen, it cannot be fixed. Replace it with a new valve designed for the dishwasher. The valve is usually fixed to a mounting bracket with screws. Disassemble the connection that links the valve to the water supply. Then remove the valve by unscrewing it. Replace it with the new valve by making the connections in reverse order.

Maintenance of the Drain Valves

Servicing the Drain Valves

Drain valves are only present in dishwashers with non-reversible motors. When these valves malfunction, call a professional service person for assistance.

Maintenance of the Heating Element

The heating element is used to assist in drying the dishes. In most dishwashers, it fits around the screen at the bottom of the tub housing and looks like an electric oven element. The heating element rarely malfunctions but may burn out. If you suspect a faulty element:

Step 1: Test it with a VOM set to the RX1 scale. Remove the dishwasher’s bottom access panel and disconnect one of the power leads to the element. Clip one probe of the VOM to each element terminal. If the meter reads between 15 and 30 ohms, the element is working. If the reading is higher than 30 ohms, the element is faulty and should be replaced.

Maintenance and Repair for Your Dishwasher

Step 2: If necessary, exchange the heating element with a new one designed for the dishwasher. Disconnect the electrical connections to the screws of the element’s terminal and remove the nuts or other attachments that secure the element to the terminals. From the inside of the tub, lift the element out, which may be held by clips and ceramic blocks in the tub, but you can easily pass it past these spacers. Place the new heating element in position, reconnect the power connections, and replace the fasteners that hold the element in place.

Servicing the Detergent Dispenser

The soap dispenser can be affected by accumulated detergent from previous washes. Build-up can get into the soap dispenser and interfere with the spring that triggers the flip-out tray, or it can slow down the pivot action of the tray. If the dispenser is not opening, first make sure that dishes or pots and pans are not touching the dispenser, and that dish racks are not blocking the dispenser. Also, check to make sure the dispenser tray is not cracked. If leftover detergent in the tray is almost liquid, rather than just damp, the tray may be damaged.

If the problem cannot be easily resolved, replace the entire dispenser unit. This is usually easier than trying to disassemble it and replace separate parts. Use a new dispenser designed for the dishwasher. The screws holding the dispenser in place may be on the front of the unit, or you may need to remove the front door panel to get to the screws and make the replacement. Remove the old dispenser and secure the new one, connecting it in the same way as the old unit was attached.

Troubleshooting Dish Racks

Problems with the dish racks usually occur because the racks have been forced back into the tub housing after they are fully loaded. Careless handling can exert enough force to crack or break the roller wheels or throw the racks off the tracks. The solution is simple: avoid forcing the racks.

The repair is also simple. Remove the racks by pulling out the small metal pins that hold them in the tracks. Or simply lift the racks and remove them from the tracks. Then reinstall the racks on the tracks so that they roll smoothly. If the rollers are cracked or broken, replace them with new ones of the same type. The rollers may be friction-fit to their hubs, so pull them off for replacement. Or, if they are held by tiny spring clips, pull the clips out with pliers or pry them out with the tip of a screwdriver. If you cannot remove the rollers for replacement, remove and replace the entire rack.

A noisy wash cycle or water that won’t drain are problems that, for the most part, can be handled by yourself. We’ll discuss how you can pinpoint these water-related problems in the next section.

Motor and Water-Related Repairs

Keeping the dishwasher’s sprayer arms, strainers, and water pump clean will help prevent problems before they start. Here’s how to check these important features.

Cleaning the Sprayer Arms of Your Dishwasher

The sprayer arms of your dishwasher usually work without any issues. However, sometimes the spray holes in the arms can become clogged with detergent or minerals. This can make the arms less efficient, and they will need to be cleaned out. To do this, you will need to remove the lower arm by twisting off the cap that holds it to the motor shaft. Wash it thoroughly with mild household detergent and water. Use the tapered end of a lead pencil or a wooden manicure stick to ream out the holes. Avoid using toothpicks, matches, or metal objects as they can cause blockages or enlarge the ports. After cleaning, place the sprayer arm back on the motor shaft and twist the cap back on to hold it in place. You can follow the same procedure to clean the upper sprayer arm.

Removing and Cleaning the Strainer of Your Dishwasher

The strainer in your dishwasher is located directly under the lower sprayer arm. If it becomes clogged with food and detergent debris, your dishwasher may flood or overfill. The strainer may be a plastic or metal component consisting of two semicircular halves, or a one-piece component. To remove the strainer, pry it up or remove the cap that holds the sprayer arm on its shaft, and then remove the sprayer arm and the strainer. Wash the strainer in the kitchen sink with mild household detergent and water. Use a fairly stiff brush to remove debris from the holes and slots in the strainer. Rinse the strainer well and replace it. If part of the strainer lifts out for regular cleaning, check and clean it after each load of dishes is washed.

Troubleshooting Leaks in Your Dishwasher

If your dishwasher is leaking and it’s not due to tub overfilling, pump or inlet valve problems, the plumbing connections may be faulty. Most dishwashers are connected to the water supply with metal pipe fittings, and the leak could be at these fittings. If the fittings are threaded, tighten them with an adjustable wrench. If this doesn’t work, chances are the threads are stripped or the fitting is cracked or otherwise damaged. In this case, replace the fitting. Check for water leaks around inlet valves, drain valves, and anywhere you see flexible hoses and hose connections. Leaks at clamps can be stopped by tightening or replacing the clamps, while leaks in hoses can be eliminated by replacing the hoses.

Maintaining the Water Pump

The water pump in most dishwashers is located under the lower sprayer arm, and it is responsible for pumping water throughout the machine. However, it can become clogged with food or detergent, which can cause problems. Here is how to disassemble and maintain the pump:

Step 1: Remove the cap that holds the sprayer arm on.

Step 2: Remove the sprayer arm, the screen, the pump housing, a bolt, the upper impeller, the food disposer blade, a spacer plate, the impeller hood, a flat plate, an O-ring, and the lower impeller. It is important to lay the components out in order so that you can reassemble them correctly.

Step 3: Thoroughly clean the parts using a mild detergent solution. If any parts are worn, replace them with new ones made for the dishwasher.

Step 4: Replace any seals, such as the O-ring or other washers, with new ones.

Step 5: Reassemble the pump, keeping the parts in order.

On some models, the lower impeller is used as a drain pump and has a reversible motor. If the water is not draining from the dishwasher, try cleaning the lower pump impeller. If this does not solve the problem, call a professional service person.

Fixing the Motor

If the dishwasher motor malfunctions, do not attempt to repair it yourself. Instead, call a professional service person to make repairs or replace the motor. Before you call for service, check to ensure that the timer is working and that the dishwasher is receiving power.

Do not let water leaks, noise, soap spots, or other issues prevent you from using your dishwasher. If you follow the guidelines outlined in this article, most problems can be resolved on your own.

©Publications International, Ltd.

FAQ

1. What are the common problems that can occur with a dishwasher?

Some common problems that can occur with a dishwasher include clogs in the drain or spray arm, malfunctioning pumps or motors, faulty door latches, and issues with the heating element. Additionally, if the dishwasher is not properly loaded or the wrong detergent is used, it may not clean dishes effectively.

2. How can I troubleshoot a dishwasher that is not draining?

If your dishwasher is not draining, start by checking the drain basket and removing any debris that may be blocking it. You can also try running a cycle with a mixture of vinegar and baking soda to help break up any clogs. If these methods do not work, you may need to check the drain hose for kinks or damage, or clean the dishwasher’s filter.

3. What should I do if my dishwasher is leaking?

If your dishwasher is leaking, first check the door gasket to make sure it is properly sealed. If the gasket appears to be in good condition, check the spray arm and spray arm seal for any cracks or damage. You may also need to check the dishwasher’s water inlet valve and float switch for issues.

4. How can I fix a dishwasher that is not cleaning dishes thoroughly?

If your dishwasher is not cleaning dishes effectively, start by checking the spray arm and making sure it is not clogged or damaged. You can also try cleaning the dishwasher’s filter and checking the water pressure to make sure it is sufficient. Additionally, make sure you are using the correct amount and type of detergent for your dishwasher.

5. Can I repair my dishwasher myself, or do I need to call a professional?

Depending on the issue, you may be able to repair your dishwasher yourself. However, if the problem is more complex or involves electrical components, it is recommended to call a professional. Always make sure to follow safety guidelines and turn off power to the dishwasher before attempting any repairs.