How to diagnose common dishwasher problems

From leaks, to cold water and noisy machines, we’ve broken down what might be going wrong with your dishwasher.

If your dishwasher is acting up then there might be a solution that can save you from the horrors of hand washing. 

Leaks

Dishwasher leaks are usually easy enough to identify. Check the following things:

  • Too much detergent - make sure you're not overloading on detergent. A soapy residue in the detergent tray will indicate that you're being a bit too generous with your cleaning solution.

  • Properly stacked dishes - are your dishes stacked properly? Overloading or poor stacking could be at the root of the problem. Make sure you don't cram too much into the machine, and that all items are stacked properly in the trays.

  • Door seal - is the seal around the door old and worn? If so, check your owner's manual to find out the correct part number for a replacement seal.

  • Pipe connections - make sure that the pipe connections at the back of your machine are in good condition and fastened correctly.

In the worst case scenario your machine might have corroded at the bottom, in which case the only solution is to replace your dishwasher.

Not Filling

If your dishes are coming out dry and dirty then your machine is not filling with water.

Check under the sink and make sure the hot water stop valve is fully open. If it is, check your owner's manual to see whether you can access the water inlet valve; this might be clogged up with debris and need clearing out.

If you’re still having some trouble with your machine, we recommend calling in a professional appliance engineer.

Not draining

A little water left in the tub is normal, but if you're worried about the amount of water left after each wash then check the following:

  • Is your drain hose damaged?

  • Are your drains blocked?

If neither of these applies then you might need a new pump. Check your owner's manual for advice on replacing your dishwasher's pump assembly.

Not Washing

If your plates are still dirty after a wash cycle then there's a good chance that poor loading is the culprit.

When stacking your dirty dishes make sure you don't just pile them into the machine. Plates may be in the way of others, meaning that the water and detergent just won't reach them.

If the problem continues you can try adding more detergent, but if that doesn't do the trick it's time to pick up the phone and have a chat with an expert appliance engineer.

Not taking the detergent

You may be putting in too much of the soapy stuff. Your dishwasher will only use the amount needed to clean the plates inside it. Use less detergent for a couple of runs and see if that helps.

Water is cold

If you suspect the water is not heating properly:

  • Hold a thermometer under the hot water tap for two minutes.

  • Check that the water is at least 140 degrees Fahrenheit (60 degrees Celsius).

  • If it's not hot enough then turn up the dial on your hot water heater.

Excessive Noise

There are a number of factors that can result in your machine being a bit too noisy. There may be some loose or worn parts, or you could just be stacking your plates badly.

When the machine is cold, look around the inside for any hard objects such as bones, fruit stones or errant knives and forks and remove these from the machine.

Make sure the unit is on a level surface. If the noise is a 'thump' then your water inlet valve may be in need of replacement.

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