Appliance repairs can be expensive, but figure out how to fix things yourself and you'll feel pretty awesome, and earn bragging rights for months. You'll also save the cost of call-out fees for what could be a very simple problem.
The most common dishwasher problems are related to dishwasher detergent, rinse aid, how you load your dishes and the type of soiling you subject them to. Check your instruction manual first to see whether it suggests a fix. If you have an error code, all the better, as the manual will generally have a breakdown of what it means.
Dishwashers can be noisy, ranging at the highest levels between 35dB and 56dB – that is, between the volume of a whispered conversation to a normal level conversation. The noise will range between different wash and rinse cycles, but if you're hearing really loud noises coming from the dishwasher, it's likely that some plates or other items are bumping against each other or that something is loose within the cabinet. Make sure that plates and glasses are secure in the racks. Some dishwashers come with hooks or racks to lock items in more securely.
Noises can also be caused by spray arms not rotating, so pause the dishwasher to check the arms can freely spin and no plates are stopping them from rotating. Some dishwashers come with sound-proofing material that should be installed prior to use; it usually looks like foam or cloth attached to a plate.
Most manufacturers recommend installation by a licensed professional. Learn more about installing a dishwasher.
Dishes: Don't rinse your dishes before you rack them. When you rinse your dishes beforehand, the automatic sensor in your dishwasher gets confused and thinks it's washing a much cleaner dish, so uses much less energy and water. That means it's more likely your dishwasher will leave dirt on the dishes, because you're not giving it the chance to tell how much dirt is really on your dishes. So just scrape foodscraps into the bin and go.
Detergent: A good quality dishwasher detergent makes a huge difference to your dishwasher's performance so choose a good one. And follow the manufacturer's instructions, because too little or detergent that's too old can have a big effect effect on the cleanliness of your dishes. If your water is hard it will affect the amount of detergent you need (as well as salt for your dispenser if required). Check the manual for precise dosage requirements.
Loading: Only wash items that are labelled dishwasher safe. Once in a while you may need to use a program that's more intensive than normal. We test dishwashers using the machine's default or automatic setting, but hard, baked-on dirt can be difficult to remove so experiment with the wash programs to see if they improve results. In rare cases, you'll need to soak your pots or pans prior to loading into the dishwasher.
Where you place your dishes matters; do your best to make sure they avoid shadowing each other, as this will prevent detergent and water from getting to dirty areas. Leaning plates against each other will also create contact points for water and dirt to accumulate. If you can, adjust the basket tines or plate racks (the vertical spikes that support your dishes) to accommodate each plate without touching another.
Your manual will most likely contain recommendations for the best places to put common items. For instance, many use the lower basket for pots and pans. Small, light items can bounce around from the pressure of the spray arms during a wash and prevent either the filter from working when they get lodged in it, or the spray arms.
Filter: Every dishwasher has at least one filter, which needs to be periodically cleaned; check your filters to make sure they're clean and have been fitted correctly – an incorrectly fitted filter could be why your dishes come out dirty.
Spray arms: Check that the spray arms can turn freely within the cabinet and that no plates or long utensils are blocking them. Some dishwashers allow you to remove the arms to clear blocked nozzles. If your manufacturer advises it, you can dig larger particles of dirt out of the spray arms with a thin, pointed object such as a toothpick.
Water: Dishwashers often specify the water pressure required to operate effectively. Check with your water supplier to see that your water pressure meets the specifications.
Opening the door a little straight after the program stops will aid drying, as will making sure the dishwasher is fully loaded (more plates means more thermal mass, which retains heat and aids drying ability), however plastic doesn't retain heat, so won't help. Plastic items can also be quite light and flip during washing and fill with water. As a rule, more intensive settings use higher temperatures which give better drying performance as well as washing. Some dishwashers also have program options that may improve drying, but they will more than likely use more energy. The rinse aid setting may need to be adjusted, or refilled. How you load can also affect drying performance. Cups, glasses, pots, bowls or mugs with deep recesses need to be loaded on an angle so water can drain out rather than accumulate.
Your dishwasher uses rinse aid to help prevent spots or film on your plates, so if you're experiencing this then adjust your rinse aid setting. Check the rinse aid setting of your instruction manual. Too much of it can cause streaks or stains and too little means water won't sheet off the dishes as well as possible. Lipsticks and tea can also be difficult to remove, so experiment with programs or wipe prior to loading into the dishwasher. If you place glasses so they lean against each other, they may develop a staining point where they touch – there is also the possibility they may break from knocking against each other.
Some food items (mustard, vinegar, lemon, salt, and mayonnaise, for example) can leave permanent spots if left on your cutlery for a long time. Minimise this possibility by scraping off as much as possible if you're not running your dishwasher straight away. Dishwashers can also leave black or grey marks on aluminium as well, so best to hand wash instead.
Periodically cleaning the filter will help to maintain the dishwasher. Some dishwashers have both coarse and fine filters, so remember to clean both. It's also a good idea to wipe over the seals of the dishwasher with a damp cloth and in any corners where dirt and grime can accumulate.
Using a higher temperature program once a month can also aid in getting rid of any smells, and some dishwashers come with a cleaning program. You can also try running a normal program with detergent, but without loading the dishwasher. Using any abrasive cleaners, solvents or scouring cloths on the dishwasher, internally or externally, is not recommended.
If there is water left over in the dishwasher after a wash, there are a couple of things you can check: that the filter is not blocked, that it's locked into its appropriate place, and that the pump area is not blocked by any debris. Also check the drainage hose for blockages and kinks.
If your dishwasher isn't filling, check the water inlet tap to see if it's turned on and that it is not blocked or restricted with limescale – often this will have a filter as well so check and clean it periodically under running water. Dishwashers are sensitive to water pressure and very low water pressure means it may not fill. Check with your local water supplier.
Some dishwashers come with touch controls, requiring only a light press to activate. If these stop functioning, it may be that the touch controls have been touched too soon after opening. You may need to wipe your controls over with a damp cloth as they are too dirty and no longer recognise touch. You may also have inadvertently activated the child lock, which you'll need to deactivate before controls will work. Consult your manual for how to to deactivate child lock controls.
Of course, the best way to avoid problems is to buy the right dishwasher in the first place. See our dishwasher buying guide.