Common Dishwasher Problems We Fix

Dishes Come Out Dirty or Gritty

It is incredibly frustrating to run a full cycle only to find food particles stuck to your plates or a gritty residue inside cups. This often indicates poor water circulation or filtration issues. In Grafton, mineral buildup from hard water can also clog spray arm jets, reducing the force of the water needed to scrub the dishes clean.

Likely causes:

• Clogged or broken spray arms
• Blocked fine particle filter or chopper blade
• Malfunctioning wash motor or diverter valve
• Inlet valve not letting enough water in
• Detergent dispenser failing to open
• Water temperature too low

How we diagnose it:

We start by checking the water level inside the tub to ensure the pump has enough water to work with. We inspect the spray arms for debris and verify they rotate freely. We also test the water temperature to ensure it reaches at least 120 degrees Fahrenheit, which is necessary for detergent activation.

What you can do right now:

Check the bottom of the dishwasher and remove the filter screen. Clean it thoroughly under hot running water to remove any trapped food debris or labels.

Dishwasher Is Not Draining

Opening the door to find a pool of standing water at the bottom of the tub is one of the most common service calls we receive. This issue can lead to leaks and unpleasant odors if not addressed quickly. The drainage system relies on a clear path from the pump out to your sink plumbing.

Likely causes:

• Blocked drain hose or kink in the line
• Failed drain pump or obstructed impeller
• Clogged air gap (if installed on the sink)
• blockage in the garbage disposal knock-out plug
• Check valve failure allowing backflow

How we diagnose it:

We listen to the drain pump to see if it hums, which suggests it is trying to run but is jammed. We disconnect the drain hose to check for obstructions and verify that the check valve is preventing dirty water from returning to the machine.

What you can do right now:

If you have a garbage disposal, run it to ensure it is clear. If you have an air gap cylinder on your sink deck, pop the cap off and check for debris.

Water Leaking on the Floor

Water leaks can damage your flooring and cabinetry, making this a high-priority repair. Leaks can originate from the door area, the bottom of the unit, or the water supply connections. Identifying the exact source is critical to preventing ongoing damage to your home.

Likely causes:

• Worn or damaged door gasket
• Loose or cracked water inlet valve connection
• Leaking circulation pump or drain pump seal
• Split spray arm shooting water at the door vent
• Unit not level causing water to slosh over the front lip

How we diagnose it:

We remove the lower kickplate (toe panel) and run the machine while observing the underside with a flashlight. We trace drip patterns to identify if the leak is coming from a hose clamp, a pump seal, or the corners of the door.

What you can do right now:

Check the rubber seal around the door for any rips or food debris preventing a tight close. wipe it down with a damp cloth.

Dishwasher Will Not Fill With Water

If the dishwasher starts but just hums without washing, it may be starved for water. Without water, the heating element can overheat and the pump cannot generate pressure. This effectively renders the appliance useless until water flow is restored.

Likely causes:

• Defective water inlet valve (solenoid)
• Stuck overfill float switch thinking the tub is full
• Clogged inlet screen on the valve
• Door switch not engaging fully
• Control board not sending voltage to the valve

How we diagnose it:

We use a multimeter to test the solenoid on the inlet valve for continuity. We also manually move the float switch to ensure it clicks and moves freely. If the valve has power but does not open, we replace the valve.

What you can do right now:

Verify that the water supply shut-off valve under your sink is fully open. Sometimes items under the sink can bump the valve closed.

Dishwasher Will Not Start or Has No Power

A dishwasher that appears completely dead or unresponsive to button presses is a major inconvenience. This can be a simple power issue or a failure of the main computer that runs the appliance.

Likely causes:

• Tripped circuit breaker or blown fuse
• Thermal fuse blown due to overheating
• Broken door latch or strike plate
• Bad user interface or control panel
• Main control board failure
• Loose wiring connection in the junction box

How we diagnose it:

We verify voltage at the junction box where the house power connects to the dishwasher. We test the door switches to ensure they are closing the circuit. If power is present but the display is dark, we test the thermal fuse and the user interface ribbon cable.

What you can do right now:

Check your home’s electrical panel to see if the breaker for the dishwasher has tripped. Reset it once to see if power returns.

Dishwasher Making Loud or Strange Noises

While modern dishwashers are designed to be quiet, they will never be silent. However, loud grinding, thumping, or high-pitched squealing noises are not normal. These sounds usually indicate a mechanical obstruction or a failing motor component.

Likely causes:

• Hard object (glass, bone, pit) in the chopper blade
• Worn bearings in the circulation or wash motor
• Drain pump impeller hitting debris
• Spray arm hitting a tall dish or utensil
• Water hammer in the inlet pipes

How we diagnose it:

We identify when in the cycle the noise occurs (draining vs. washing). We inspect the pump housing and chopper assembly for foreign objects. If the noise is a high-pitched squeal, it often points to motor bearings that require a motor replacement.

What you can do right now:

Spin the spray arms by hand before starting the cycle to ensure they do not hit any tall plates or silverware in the baskets.

Dishes Are Not Drying

Opening the dishwasher to find dripping wet plates is disappointing. Drying issues are common, especially in newer energy-efficient models that rely on condensation drying rather than heating elements. However, total failure to dry usually points to a specific component malfunction.

Likely causes:

• Burned out heating element
• High-limit thermostat cutting power to the heater
• Vent fan failure (in models with active venting)
• Empty rinse aid dispenser
• Malfunctioning turbidity sensor

How we diagnose it:

We test the heating element for electrical continuity. We also check the operation of the vent fan assembly. If the unit uses a specialized drying system like a zeolite container, we inspect that system for proper function.

What you can do right now:

Ensure your rinse aid dispenser is full. Rinse aid breaks the surface tension of water, allowing it to sheet off dishes and dry much faster.

Cycle Runs Too Long or Never Finishes

If your dishwasher runs for four or five hours, or gets stuck on “1 minute remaining” indefinitely, there is an issue with the cycle logic or heating. The machine often pauses the timer while waiting for water to reach a specific temperature.

Likely causes:

• Heating element not warming the water
• Thermostat or thermistor reading incorrect temperature
• Control board software glitch
• Clogged filters slowing down drainage and refill
• Sensor issues detecting soil level

How we diagnose it:

We monitor the water temperature during the wash cycle to see if it rises. If it stays cold, the timer will often stall. We test the thermistor to ensure it sends the correct resistance values to the main board.

What you can do right now:

Run the hot water at your kitchen sink until it is steaming hot before you start the dishwasher. This primes the line and reduces the work the dishwasher heater must do.