Dishwasher owners have told us they expect their dishwasher to last at least 10 years without breaking down. But we’ve found that many become faulty much earlier.
Our dishwashers research shows us that more than a fifth of dishwashers develop a fault within eight years, and one in 10 within the first two years.*
The most commonly reported faults are:
- Stopped cleaning as well: 12% of all faults
- Stopped draining properly: 9% of all faults
- No longer drying properly: 7% of all faults
But some of these can be prevented before they happen.
We’ve rounded up the top five ways to make your dishwasher work better, avoiding many common problems, and last longer.
Get a reliable dishwasher in the first place: top dishwasher brands
1) Fix poor drying with rinse aid
The rinse aid compartment is right next to the detergent dispenser on the inside of the dishwasher door. Rinse aid helps your dishes get dry by letting water run off more easily. It can also help prevent water marks.
If you’re not happy with how dry dishes and glasses are, you just can increase the amount of rinse aid used by your dishwasher: just twist the dial under the rinse aid lid to a higher setting.
2) Get cleaner dishes with salt
In order to achieve good cleaning results, dishwashers need to use very soft water. Hard water can lead to a white film developing on crockery, glasses and the insides of your dishwasher. It can also damage the heating element and jets.
This is where dishwasher salt comes in.
The sodium in dishwasher salt combines with resin balls in your dishwasher’s workings to absorb the hardness.
The resin balls have a negative atomic charge and the dishwasher salt has a positive atomic charge. The calcium and magnesium swap with the sodium ions, removing the hardness and softening the water.
When the resin balls’ sodium stores are exhausted, adding dishwasher salt resets them, so they can absorb more.
You can’t use regular table salt
Only buy salt that is specifically labelled for dishwashers. Dishwasher salt granules are larger, which ensures that they dissolve slowly and don’t block the water softener.
Dishwasher salt doesn’t contain added anti-caking agents or magnesium salts, like table salt can. Unsurprisingly, the presence of magnesium salts will defeat the purpose of removing magnesium (which is helping to make water hard).
Adjust the salt setting to suit water hardness
To find out how hard the water in your home is, ask your supplier – you can usually find the information online. It will be able to give you the concentration of calcium and magnesium ions, usually in millimole per litre (mmol/l). Then consult your dishwasher’s manual to find out which setting will work best.
Only put salt into the softener unit
Many come with a handy funnel to make topping up the salt easy. Most dishwashers now have a salt refill light. If your dishwasher doesn’t have indicator lights, it’s a good idea to refill the salt about once per month.
The salt you pour in the softener unit never actually touches your dishes; it just stays in the unit itself. If you leave loose salt in the dishwasher, not only will it not work properly, but it may also give you slightly dirty (or salty) dishes.
And don’t put salt into other spots marked for normal detergent, dishwasher cleaner or rinse aid. This could easily break your appliance.
3) Give all-in-one tablets a helping hand
We asked the experts at Bosch why your dishes could be coming out dirty, wet and with watermarks.
It told us that many people assume that an all-in-one detergent tablet will cover all of their salt and rinse aid needs, but it always recommends keeping them both topped up, no matter what type of detergent you’re using.
This is because all-in-one tablets only reduce the amount of salt and rinse aid used over time, and don’t completely remove the need to use it.
Poor cleaning could also be caused by lacklustre detergent. Make the most of your dishwasher by choosing one of the Best Buy dishwasher tablets.
4) Shift fats, oils and leftover food
Our top tip is simply to clean regularly.
Run the dishwasher every six months with a dishwasher cleaner (or a dose of diluted lemon juice or vinegar) to help clean out the interior and the pipework. For this you should use an intensive or hot programme – particularly if you normally use a lower temperature (50°C or lower) one. A hotter wash will help to shift accumulated fats and oils from the drain hoses.
Don’t use bleach or harsh cleaners, though. This can degrade the dishwasher seals and components and cause damage to the machine.
Beko recommends that you clean the filter once a week.
Tip: To remember to clean your filter, get in the habit of having a quick look at the filter (without removing it) whenever you pull out the lower rack. That way you can check if there’s a build-up of debris.
Other key cleaning tasks include wiping the door seals, which you should do weekly – you can even use a smear of petroleum jelly to keep them supple.
Every few months you should check for and remove any blockages in the spray arm holes, too. Just remove the spray arm and poking through the holes with a toothpick or the bristles of a brush.
Get a full run-down of what to do: how to clean a dishwasher
5) Check your dishwasher’s drainage
Experts at Miele tell us that poor installation could be why your dishwasher isn’t doing a very good job.
A dishwasher that’s been poorly installed could squeeze on the waste hose, leading to drainage issues.
If the dishwasher’s feet aren’t adjusted to keep the machine level this could make the door catch or make it difficult to close.
Go to our full guide on how to drain a dishwasher to watch our step-by-step video.
*We surveyed 4,012 Which? members between September and October 2018 to find out when their dishwasher experienced a fault, what problems they encountered and how happy they are with their dishwasher.