Dishwasher Keeps Filling With Water? Causes and What to Do Right Away

If your dishwasher keeps filling, turn off the water supply under the sink first, then switch off the dishwasher at the breaker or unplug it. The usual cause is a water inlet valve stuck open. Next most likely are a stuck float, a faulty float switch or timer, and sediment in the supply. Check the float, then replace the valve or call a technician. Do not run the machine again until it is fixed.

You come back to a dishwasher that is full of water long after the cycle ended. Or you open the door and hear water still running. Or you wake up to a wet kitchen floor. A dishwasher that fills and does not stop is a flooding risk, so the order of what you do matters.

This guide first tells you how to stop the water, then explains the likely causes in the order repair technicians check them. The explanations come from appliance repair forums and manufacturer help pages. Parts differ by brand, so use your model number when you buy anything.

Stop the water first

1. Turn off the water supply. The shut-off valve is usually under the kitchen sink, on the hose that goes to the dishwasher. Turn it clockwise until it stops.
2. Cut the power. Switch off the dishwasher's breaker, or unplug it if you can reach the plug.
3. Drain the tub. Bail out standing water with a cup and towel, or run the drain cycle once the power is back on and the water is still off. Do not run a fill.
4. Mop up any water on the floor, and check under the sink for leaks. If water got into the cabinet, see the signs of hidden leaks.

Leaving the water supply off until the part is fixed is what the forum technicians consistently recommend.

What the symptom tells you

Cause 1: The water inlet valve is stuck open

This is the part that lets water into the machine. It is opened by an electric signal and closed by a spring and water pressure. If it fails to close, water keeps coming in.

• Test: Turn the dishwasher's power off at the breaker. If water still flows in, the valve is the problem. One technician in a forum thread said that if water keeps flowing after the door is opened, the valve is likely bad.
• Fix: Replace the valve. It is a common repair and the part is usually inexpensive, but it involves water and wiring. If you are not confident, call a technician.
• Why it fails: A forum reply noted that a valve failing this way is not especially common, so debris or sediment in the water supply may be a factor if it happens more than once. The valve's small inlet screen can also clog.

Cause 2: The overfill float is stuck

Inside the tub there is a small float. It rises with the water and tells the dishwasher to stop filling.

1. Switch off the power and the water.
2. Look in the bottom of the tub for the float. It is usually a small plastic dome or cup, often near the front or back.
3. Lift it gently and let it drop. It should move up and down freely.
4. Clean away any food, label or broken glass that is blocking it.

Whirlpool's guidance is to check that the overfill protection float moves up and down freely and to remove anything that blocks the float area. If it moves freely and the problem remains, the float switch may be faulty.

Cause 3: A bad float switch or timer

The float is connected to a switch. If the switch fails, it may not cut off the water. A forum technician suggested a test: measure the voltage across the fill valve. If the voltage drops and the dishwasher keeps filling, the valve is at fault. If the voltage continues past the normal fill time, the timer or control is the likely problem.

That test uses a multimeter on live wiring. Leave it to a technician unless you are trained.

Cause 4: Low water pressure or a dirty supply

Whirlpool lists inadequate pressure as a cause of fill problems. Debris in the water line, a partly closed shut-off valve or a clogged inlet screen can all upset the fill. If you have well water or old pipes, sediment can clog the valve. Turn off the water, disconnect the hose and check the small screen at the valve for debris.

If the water in your home has a lot of sediment or minerals, our guide to adding a whole-house water filter explains one way to protect your appliances.

For a portable dishwasher

Portable models have one more thing to check: the drain hose. Whirlpool says the loop at the end of the drain hose should be at least 20 inches above the floor. A hose that is too low can let water siphon or flow back, which can look like a dishwasher that will not stop filling. Check your own manual for the exact figure for your model.

When it fills but also will not drain

If the tub is full of water and stays full, you may have two problems or a drain problem. See a dishwasher that will not drain for the drain pump and clog checks.

When to call a technician

Call an appliance technician or plumber if:

• Water keeps flowing with the power off, and you are not comfortable replacing the valve.
• The float moves freely but the problem continues.
• You find water under the sink or in the cabinet.
• The machine is old, and several parts are failing.
• You are not comfortable working with water lines or wiring.

Give them the make and model, say that the water keeps running when the power is off (if it does), and tell them what you checked.

Repair or replace?

Ask for a written estimate before repair starts.

What not to do

• Do not run the dishwasher until the cause is fixed.
• Do not leave the water supply on while you wait for a part.
• Do not test the valve or timer with power on unless you are trained.
• Do not ignore a wet cabinet floor.
• Do not add more detergent hoping to solve it.

Which fix fits your situation?

• Water runs even with the power off: inlet valve.
• Overflows in the middle of a cycle: the float and float switch.
• Keeps filling after the cycle ends: valve, float switch or timer.
• Portable dishwasher: hose loop and height.
• Spots on the glass but no overfill: that is a different issue. See why a dishwasher leaves white residue.

Bottom line

A dishwasher that will not stop filling is a flooding risk. Shut off the water and power first. The stuck inlet valve is the most common culprit, and the float is the quickest thing to check. Replace the valve or call a technician, and keep the water off until it is done.