Common Dishwasher Problems and How to Fix Them

A misbehaving dishwasher is frustrating, but before you call a technician (and face a $150+ call-out fee), many common issues have simple solutions you can tackle yourself. After 15 years of repairing dishwashers, I can tell you that roughly 60% of service calls I attend could have been resolved by the homeowner with basic troubleshooting.

This guide covers the most frequent dishwasher problems, their likely causes, and step-by-step solutions. We'll start with quick fixes and progress to issues that might require professional help.

Problem 1: Dishes Aren't Coming Out Clean

This is the most common complaint. If your dishes emerge with food residue, spots, or film, work through these potential causes:

Check the Filter

A clogged filter is the number one culprit for poor cleaning. Food particles trapped in the filter can recirculate onto dishes.

• Remove and clean the filter under running water
• Use a soft brush to remove stubborn debris
• Clean weekly for best results

Inspect Spray Arms

• Remove spray arms and check each hole for blockages
• Clear blocked holes with a toothpick
• Ensure arms spin freely when reinstalled

Review Loading Technique

• Don't overcrowd—water needs to reach all surfaces
• Ensure items don't block spray arm rotation
• Face soiled surfaces toward the spray
• Don't nest bowls or cups

Problem 2: Dishes Not Drying Properly

Wet dishes after a cycle are annoying, especially when you need to put them away immediately. Here's why this happens and how to fix it:

Use Rinse Aid

Rinse aid is not optional—it breaks water surface tension, allowing water to sheet off dishes rather than forming droplets that remain.

• Check the rinse aid reservoir and refill if empty
• Adjust the dispenser setting (higher for hard water)
• Quality rinse aid makes a significant difference

Loading for Better Drying

• Angle items so water drains off, not pools
• Don't place plastic items on the bottom rack near the heating element (risk of melting)
• Plastic doesn't retain heat like ceramic, so it dries poorly—this is normal

Check Heating Element

If your dishwasher has a heated dry function but dishes are cold and wet:

• The heating element may have failed
• This requires professional replacement
• Consider using air dry mode and opening the door post-cycle as a workaround

Problem 3: Dishwasher Won't Drain

Standing water in the bottom after a cycle indicates a drainage problem. This needs attention before it causes odours or overflow.

Check for Simple Blockages

1. Remove bottom rack and inspect the drain area
2. Clear any visible debris or food particles
3. Remove and clean the filter thoroughly
4. Check inside the drain pump housing if accessible

Inspect the Drain Hose

• Ensure the drain hose isn't kinked behind the machine
• Check where it connects to the sink drain for blockages
• Run water through the drain hose to test for flow

Check Air Gap/High Loop

The drain hose should loop up high under the counter before going down to the drain. This prevents backflow from the sink.

Problem 4: Strange Noises During Operation

Unusual sounds can indicate minor issues or signal developing problems. Here's how to interpret common noises:

Grinding or Crunching

• Cause: Debris in the pump, hard objects (glass, pits, bones) in the drain
• Fix: Stop the cycle, clear the drain area, check for broken glass

Humming or Buzzing

• Cause: Usually normal pump operation; excessive humming may indicate blockage
• Fix: Check for obstructions in the pump area

Banging or Thumping

• Cause: Items hitting the spray arm, or spray arm hitting dishes
• Fix: Reload ensuring nothing obstructs spray arm rotation

Squealing or Screeching

• Cause: Worn pump bearings, worn spray arm bushings
• Fix: Usually requires part replacement—call a technician

Problem 5: Dishwasher Leaking

Leaks require prompt attention to prevent water damage. The location of the leak helps identify the cause:

Leaking from the Door

• Check door gasket for damage, tears, or debris
• Clean the gasket with warm soapy water
• Ensure door hinges allow proper closure
• Too much detergent causes excess suds that can leak through the door

Leaking from Underneath

• Check water inlet connection (usually at back)
• Inspect drain hose connection
• A pump seal failure causes leaks from below (professional repair needed)

Problem 6: Dishwasher Won't Start

A dishwasher that won't start or respond has electrical or control issues. Before assuming the worst:

Basic Checks

• Ensure the door is completely latched (door switch must engage)
• Check the power—is the outlet working? Try resetting at the switchboard
• Confirm the water supply is turned on
• Check for error codes on the display

Control Lock/Child Lock

Many dishwashers have a control lock feature that disables buttons. Look for a lock icon and consult your manual for how to disable it (usually holding a button for 3 seconds).

Door Latch Issues

If the door doesn't click firmly closed, the safety switch won't engage and the dishwasher won't start. Check for:

• Debris preventing the latch from engaging
• Worn or broken latch mechanism
• Door hinges out of alignment

Problem 7: White Film or Spots on Dishes

Cloudy glasses and white residue usually indicate water hardness or detergent issues:

Hard Water Solutions

• Increase rinse aid dosage
• Use a detergent formulated for hard water
• If your dishwasher has a water softener, check salt levels
• Run a cleaning cycle with citric acid or specialised dishwasher cleaner

Too Much Detergent

Excess detergent leaves residue, especially with modern efficient machines that use less water.

• Reduce detergent amount, especially with soft water
• Try switching detergent brands
• Ensure the detergent dispenser opens during the cycle

When to Call a Professional

Some problems require expert attention:

• Error codes that persist after reset—these indicate sensor or electronic failures
• Electrical burning smell—stop use immediately, unplug, and call a technician
• Motor or pump failure—requires parts and expertise
• Control board issues—beyond DIY repair for most people
• Warranty-covered issues—professional repair maintains warranty

Many problems have simple solutions you can implement in minutes. Work through the relevant troubleshooting steps before booking a service call—you might save yourself $150+ and the inconvenience of waiting for a technician.