How to clean a dishwasher – so it’s effective and efficient

Wondering how to clean a dishwasher to ensure every load is hygienic and sparkling? Like other appliances that do the cleaning for you, a dishwasher needs to be cleaned itself to avoid the development of unpleasant smells, and so it will work efficiently and have the longest possible lifespan.

Cleaning a dishwasher isn’t a particularly onerous task, but it is important to undertake the various aspects of the job regularly when cleaning a kitchen. Some need to be done weekly or monthly, while others just require attention every six months or so, and none of them will take up too much of your time.

We’ve put together all the advice you require for great cleaning results and a fresh appliance interior in the long term. 

How to clean a dishwasher

Getting in the know about how to clean a dishwasher avoids the problems of debris and marks on plates at the end of a cycle, and a malodorous machine. Follow the advice in our guide.  

1. How to clean a dishwasher filter

A dishwasher’s filter traps food debris and, unless your filter is a self-cleaning type (likely on machines 10 and more years old), it needs to be cleaned regularly to avoid some of the debris it has caught ending up back on the dishes. In other words, removing the accumulated particles is an important part of how to clean a dishwasher.

The filter can be found at the bottom of the machine. Pull out the lower rack to access it. Check the manual of your appliance but most have two parts and in order to clean it generally it’s a question of turning the cylindrical filter through a quarter turn to remove it, then gently lifting and pulling the lower metal filter towards you to take that out.

Run the faucet to clean the debris off the filter. For the cylindrical part, you might need to use a soft brush; make sure to avoid wire versions. Use dish soap, too, if the running water doesn’t remove everything. Once the filter is clean it can be replaced in the machine.

This is a task you should undertake weekly. ‘Cleaning the filter in your dishwasher‘s base regularly is crucial,’ says Smeg’s home economist, Clare Edwards. ‘This collects food particles and residue and can not only produce an odor if not cleaned but will also reduce the dishwasher’s performance.’

2. Clean a dishwasher door

Also part of the weekly process when you’re asking how to clean a dishwasher is cleaning the door. This is another part of the machine where food debris can become stuck, and if it’s not removed, the seals can degrade and the appliance could leak. 

All you need to do? Simply wipe around the door with a damp cloth.

3. Clean dishwasher spray arms

You might be prompted to clean the dishwasher spray arms because loads aren’t coming out of the machine pristine, but you should clean them about every six months in any case. ‘This is especially important if you have hard water as calcium and scale deposits will crust over the spray holes,’ says Michael Green, vice president of operations at Benjamin Franklin Plumbing. 

The spray arms can also become blocked by small food particles and, when that happens, the water won’t be distributed around the appliance as it should be. 

To clean them remove the arms from the machine according to the manufacturer’s instructions. Use a cocktail pick to poke any material out of each of the holes, then rinse the spray arms under the faucet. 

4. Run a dishwasher cleaning wash

Another answer to the question of how to clean a dishwasher is to run a cycle when the machine is empty a couple times a year.

Use a hot wash and it will get rid of food debris that can make the interior of the machine smelly. 

Hot water can be sufficient to cleanse the machine, but you might want to use a dishwasher cleaning product – for example those from from Finish or Affresh – at the same time to remove limescale and grease from the appliance. 

5. Top up salt regularly

Keeping the salt in a dishwasher topped up is important to prevent limescale buildup in the first place, so make sure you add it when the machine’s indicator shows it’s needed.

And while it isn’t part of how to clean a dishwasher itself, don’t forget that adding rinse aid as indicated is also important to help get rid of food debris and make glasses streak free. 

Is vinegar bad for a dishwasher?

Plenty of people recommend using vinegar to clean a dishwasher, but beware. ‘It's best to avoid using vinegar to clean a dishwasher because it can damage the rubber seals and hoses in some washing machines,’ says Roman Peysakhovich, CEO of national cleaning company Onedesk. That could result in a leaking machine over time.

You might see that the manufacturer of your dishwasher has advised against using vinegar because it will affect the rubber used in the components of its model and therefore, unless the manual actually says it is possible to clean with vinegar, we strongly advise you to avoid it.

Read that you can clean a dishwasher with bleach? Don’t use it either. It could cause damage.

How do you deep clean an old dishwasher?

To deep clean an old dishwasher, follow the steps above, cleaning the filter, spray arms, and the door. Run a hot wash with a dishwasher cleaner, too.

Old dishwasher got a nasty note to it? ‘The most common cause of dishwasher smells is a clogged drain filter,’ says Molly Maid president Vera Peterson, so make sure you clean this thoroughly to banish the funk.