Common Dishwasher Problems We Fix

Dishwashers are hardworking machines that combine water, heat, and electricity. Over time, components wear out or become clogged with debris. We see a wide variety of issues in Tewksbury homes, but the following problems are the most frequent.

Dishwasher Is Not Draining

Opening your dishwasher to find a pool of dirty, grey water at the bottom is one of the most common complaints we receive. This standing water can smell bad and may leak out if the door is not sealed perfectly. It indicates that the dirty water from the wash cycle cannot exit the machine, leaving your dishes unsanitary.

Likely causes:

• Blocked drain filter filled with food particles
• Kinked or clogged drain hose
• Failed drain pump motor
• Broken pump impeller
• Obstruction in the garbage disposal connection
• Check valve failure

How we diagnose it:

We start by manually inspecting the filtration system and the sump area for large debris like broken glass or bone fragments. We then test the drain pump to see if it receives power and spins freely. We also check the entire length of the drain hose for blockages and verify that the knockout plug in your garbage disposal was removed if it is a new installation.

What you can do right now:

Check the filter at the bottom of the tub and remove any visible debris. Ensure that your kitchen sink drains properly, as a clog there can back up into the dishwasher.

Water Leaking on the Floor

A leak can range from a few droplets to a major flood that damages your hardwood or tile. You might notice water pooling directly in front of the machine or seeping out from underneath the cabinetry. This is an urgent issue because water damage can spread quickly to your subfloor and lower cabinets.

Likely causes:

• Worn or torn door gasket
• Loose hose connections
• Cracked water inlet valve
• Defective pump seal
• Corroded heating element nuts
• Door latch not pulling the door tight
• Using too much detergent creating excess suds

How we diagnose it:

We remove the kickplate to inspect the underside of the unit while it runs a short cycle. We look for drips originating from hoses, the pump housing, or the motor shaft. We also inspect the door seal for rips, brittleness, or food buildup that prevents a watertight closure.

What you can do right now:

Stop using the machine immediately. Check the door seal for any obvious gaps or debris. If the leak is severe, turn off the water supply valve under the sink.

Dishes Come Out Dirty or Spotty

The primary purpose of your appliance is to clean, so it is frustrating when plates come out with food stuck to them or glasses are covered in a white haze. This often forces you to wash the load again by hand, defeating the purpose of having the machine.

Likely causes:

• Clogged spray arm holes
• Broken spray arm support
• Detergent dispenser failure
• Low water temperature
• Inlet valve not allowing enough water in
• Circulation pump failure
• Hard water mineral buildup

How we diagnose it:

We check the water temperature to ensure it reaches at least 120 degrees Fahrenheit. We inspect the spray arms to ensure they spin freely and that the jets are clear of hard water deposits or seeds. We also test the detergent cup to verify it opens at the correct time in the cycle.

What you can do right now:

Run the hot water at your kitchen sink before starting the dishwasher to prime the line. cleaning the spray arms with a toothpick can also help clear blocked jets.

Dishwasher Is Not Drying Dishes

If your dishes are soaking wet hours after the cycle ends, your drying system may be malfunctioning. Plastic items are naturally harder to dry, but ceramic and metal items should be hot and dry. This issue often leads to mold growth if the moisture is left inside the dark, warm tub.

Likely causes:

• Burnt out heating element
• Malfunctioning high limit thermostat
• Broken vent fan
• Empty rinse aid dispenser
• Control board relay failure

How we diagnose it:

We test the heating element for continuity using a multimeter to see if the electrical path is broken. We also check the vent fan operation and inspect the rinse aid assembly. Modern units often rely on condensation drying, so we verify that the intake and exhaust vents are clear.

What you can do right now:

Ensure your rinse aid dispenser is full, as this helps water sheet off dishes. Open the door slightly after the cycle finishes to let steam escape.

Unit Will Not Start

You load the racks, add soap, press the start button, and nothing happens. The lights might flicker, or the panel might be completely dead. This is a common electrical or mechanical lockout issue that prevents the cycle from initiating.

Likely causes:

• Door latch or switch failure
• Blown thermal fuse
• Tripped circuit breaker
• Broken door spring or hinge
• Control panel touchpad failure
• Main control board malfunction

How we diagnose it:

We start by checking the power supply at the junction box. If power is present, we test the door switches to ensure the machine knows the door is closed. We also check the thermal fuse, which is a safety device that cuts power if the unit overheats.

What you can do right now:

Check your home’s electrical panel to see if the breaker has tripped. Verify that the door is latching firmly and is not obstructed by a rack.

Dishwasher Making Loud Noises

While no dishwasher is silent, it should not sound like a rock crusher. Grinding, thumping, or high pitched squealing noises indicate that a moving part is failing or that a foreign object is interfering with the wash mechanics.

Likely causes:

• Hard debris trapped in the chopper blade
• Worn wash pump bearings
• Defective drain pump
• Spray arm hitting dishes
• Loose mounting brackets

How we diagnose it:

We listen to the machine during different stages of the cycle to isolate the sound. We check the pump housing for seeds, glass, or plastic bits. We also inspect the wash arm clearances to ensure they are not striking tall plates or silverware.

What you can do right now:

Check inside the tub for any loose items like spoons or bones. Spin the spray arms by hand to see if they hit anything.

Dishwasher Not Filling With Water

If you hear the machine humming but no water is entering, the wash cycle cannot happen. You might open the door mid cycle to find the bottom of the tub completely dry. Without water, the heating element can overheat and cause damage.

Likely causes:

• Failed water inlet valve
• Stuck float switch
• Clogged inlet screen
• Leak detection system activated
• Door switch failure

How we diagnose it:

We test the voltage at the inlet valve to see if the computer is sending a signal to open. If it has power but no water flows, the valve is bad. We also check the float assembly, which tells the machine when the water level is high enough, to ensure it moves freely.

What you can do right now:

Ensure the water supply valve under your sink is fully open. Lift the float switch in the tub gently and see if it drops back down smoothly.

Cycle Takes Too Long

Modern energy efficient dishwashers run longer than older models, but if your cycle is taking four or five hours, something is wrong. This wastes energy and keeps you from using your dishes when you need them.

Likely causes:

• Thermostat not sensing heat
• Heating element failure
• Sensor failure causing loops
• Clogs restricting water flow
• Cold water entering the unit

How we diagnose it:

We check the turbidity sensor which detects how dirty the water is. If this sensor is dirty, it may keep the machine washing unnecessarily. We also check the heating loop, as the timer often pauses until the water reaches a specific temperature.

What you can do right now:

Clean the interior of the machine with a dishwasher cleaner to remove mineral buildup on sensors. Run hot water at the sink before starting the load.