Dishwasher Repair Tips: Dishwasher Not Cleaning Dishes

Usually, simply cleaning the spray arm, filter and float will solve the problem

When your dishwasher doesn't clean well, fix it yourself following these simple steps and avoid the expensive professional service call. A simple cleaning often solves the problem.

By the DIY experts of The Family Handyman Magazine

Step 1: Simple cleaning solutions

If your dishwasher is running but the dishes aren’t getting clean, one of these simple fixes could solve your problem. Start by consulting your manual to be sure you’re using the right detergent, loading the dishes correctly and maintaining the right hot water temperature. Then follow Photos 1 – 5 for repair steps.

Insufficient water in the dishwasher also can cause poor cleaning. If the float gets stuck in the raised position, the dishwasher won’t fill with water (Photo 3). Another likely cause is a clogged inlet screen or faulty inlet valve. Photos 4 and 5 show how to clean the screen or replace the valve. To determine if your dishwasher is getting enough water, start a wash cycle. Open the door when you hear the machine stop filling. The water should reach or come close to the heating coil. If it doesn’t, first make sure the float valve is operating freely (Photo 3). If this doesn’t solve the problem, check the inlet valve and screen.

Figure A: Anatomy of a Dishwasher

Follow this diagram to locate the basic dishwasher parts.

Dishwasher parts
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Step 2: Replace the inlet valve

Inlet valves that are starting to fail sometimes make a hammering noise. If you hear this, replace the valve. But before you start any work on the dishwasher, unplug it or turn off the power at the shutoff switch or main circuit panel. Test to see if the power is off by turning on the dishwasher and making sure it doesn’t run. You’ll also have to shut off the water before removing the inlet switch. Usually you’ll find a shutoff valve under the kitchen sink or in the basement or crawl space under the dishwasher. Otherwise, close the main water valve.

Photo 4 shows how to remove the inlet valve. Yours may look different. Whether you’re replacing the valve or simply cleaning the screen, you’ll have to unscrew the brass fitting that connects the water line to the valve. Remove the four screws that secure the valve to the bracket to access the filter screen (Photo 5). Reassemble and reinstall the valve in the reverse order. Wrap Teflon tape around the fitting threads before screwing the fitting into the valve.

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Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • Nut driver
  • Pliers
  • Shop vacuum