Dishwasher not draining? Why there's water in the bottom and how to fix it

A pool of dirty water in the bottom of the dishwasher after a cycle is the fault our engineers get called out to more than any other. Won't drain is around 23% of our recent dishwasher repairs. A good few turn out to be a blocked filter, which is a ten-minute job, so here are the checks worth doing before you book anyone.

Safe checks you can do first

Turn the dishwasher off at the wall, and get towels and a shallow container ready, because you'll be lifting water out.

Scoop the standing water out with a cup, then a sponge for the last of it, until you can see the base. Now take the filter out. It's the round plastic piece in the bottom, usually a twist to unlock. Under it, in the sump, is where food, glass and the odd label collect. Rinse the filter under the tap and clear anything left in the sump below it. Our guide on cleaning the dishwasher filter goes through it properly.

Check the drain hose next. It runs from the back of the machine to the waste under the sink, and it kinks easily where the machine's been shoved back into its gap. Follow it and make sure nothing's crushed or bent sharp.

Last, look at where it drains into. Most dishwashers empty into a spigot on the sink waste or trap. If that's blocked, or a newly fitted machine still has the blanking cap on the spigot, the water has nowhere to go. Pour some water down the sink and check it runs away.

Run a short cycle once you've done all that. If the water clears, you're sorted.

When it's a repair

Filter clean, hose clear, waste running away, and still a puddle in the bottom. Now the fault's inside the machine. The drain pump is the usual answer, and it's one of the parts we replace most on dishwashers. It either fails silently or hums but shifts no water, and either way the cycle stops before it drains. A blocked pump does the same, when something small gets past the filter and jams the impeller. There's the electrical side too. A pressure sensor that wrongly reads the machine as empty, or a control fault, both show up as a machine that won't drain. That's the point to get an engineer out, since it means working on a mains appliance sitting in water.

What a repair costs

Our band for a dishwasher that won't drain is £85 to £150, with any parts quoted separately and the price confirmed before we start. The engineers carry the common parts, so most repairs are done in one visit.

Book a dishwasher repair

If you've cleared the filter and hose and there's still water in the bottom, book a dishwasher repair or find your local dishwasher engineer.

Frequently asked questions

Why is there water in the bottom of my dishwasher?

Usually a blockage in the filter, sump, drain hose or the sink waste it drains into. When it isn't a blockage, the drain pump is the most likely cause, though a faulty pressure sensor or control fault look the same from outside.

How do I drain a dishwasher that's full of water?

Scoop and sponge the standing water out, take out the filter, and clear the sump underneath. Then check the drain hose isn't kinked and the sink waste runs freely.

Can I fix a dishwasher that won't drain myself?

Often, yes. Clearing the filter, sump and drain hose is a reasonable job. Opening the machine up to reach the pump isn't, and neither is anything electrical.

How much does it cost to fix?

£85 to £150 for this fault, with any parts quoted separately and the price confirmed before work.