How to Clean a Dishwasher: Filter, Spray Arms and Seals

A dishwasher cleans your plates, but it doesn't clean itself. Food, grease and limescale build up inside, and in a few months you'll notice:

• a bad smell when you open the door
• bits of food or grit left on plates and glasses
• cloudy glasses or white marks
• water left sitting in the bottom after a cycle

The good news is that it takes about 20 minutes to fix. Here's how.

What you need

• Rubber gloves
• A soft brush or an old toothbrush
• A cloth and washing-up liquid
• A bowl of warm water
• A cocktail stick or toothpick
• Dishwasher cleaner

Check your manual first. Every machine is a little different. Some makers advise against white vinegar, because it can wear out rubber seals over time, so a dishwasher cleaner is the safer choice.

Step 1: Empty it and take out the racks

Take out the bottom basket and the cutlery basket. This gives you room to reach the filter and the bottom of the machine.

Step 2: Clean the filter

This is the most important step. The filter catches food so it doesn't go back onto your dishes, and a blocked filter causes most smells.

1. Find the filter in the bottom of the machine, usually under the lower spray arm.
2. Twist it and lift it out. Most have a round part and a flat mesh part.
3. Rinse them under a warm tap.
4. Scrub gently with a soft brush and a little washing-up liquid. Don't use a wire brush, as it can damage the mesh.
5. Wipe out the hole the filter sits in, then put the filter back until it clicks or locks.

Step 3: Clear the spray arms

The spray arms spin and spray water onto your dishes. If their small holes are blocked, parts of your dishes won't get clean.

• Look at each hole. Push out any food or limescale with a cocktail stick.
• Many spray arms unclip. If yours do, rinse them under the tap and shake out any water.
• Check they spin freely when you put them back.

Step 4: Wipe the door seal and edges

Dirt collects in the rubber seal around the door and along the bottom edge of the door, where the water doesn't reach. Wipe them with a cloth and warm soapy water. An old toothbrush helps in the corners.

Step 5: Run a cleaning cycle

With the dishwasher empty, run it on the hottest programme with a dishwasher cleaner, following the instructions on the pack. This removes grease and limescale from the parts you can't reach.

Step 6: Clean the outside

Wipe the door and control panel with a damp cloth. For stainless steel, wipe in the same direction as the grain and dry it with a soft cloth to avoid streaks.

How often should you clean a dishwasher?

Job	How often
Rinse the filter	Every 1–2 weeks (monthly if you use it less)
Wipe the door seal and edges	Once a month
Cleaning cycle with dishwasher cleaner	Once a month
Check the spray arms	Every 2–3 months

Keep it cleaner for longer

1. Scrape plates, but don't rinse them. Modern dishwashers work best with a little food on the plates.
2. Keep salt and rinse aid topped up. London has very hard water, which causes limescale and cloudy glasses. Which? explains how dishwasher salt and rinse aid work.
3. Run a hot programme now and then. Short, cool cycles let grease build up.
4. Leave the door open a little after a cycle, so it can dry out and doesn't smell.

For more tips, see the Which? guide on how to clean a dishwasher.

Short on time?

A dishwasher is quick, but a whole kitchen isn't. A TidyGo deep clean covers inside the oven, fridge and microwave, inside cupboards and descaling, and an end of tenancy clean cleans all appliances inside and out. Deep cleans cost £22 an hour per cleaner. See our prices.

Like greener products? See our guide to eco-friendly cleaning products.

Fighting limescale? Read our guide to removing limescale in London's hard water.