Water left in the bottom of the dishwasher: what to do

Dirty water sitting in the dishwasher usually means something simple is in the way.

The answer in 2 lines. If dirty water is still sitting in the dishwasher after a cycle, it isn't draining properly. The usual causes, in order: a blocked filter, a squashed or kinked drain hose, or a blocked sink waste pipe that the dishwasher drains into. Less often, it's the drain pump. Unplug the dishwasher, scoop out the water, then check those in that order. Call a repairer if the pump hums but nothing drains, if it makes no sound at all, or if water is leaking onto the floor.

The first 3 steps

Unplug the dishwasher, or switch it off at its switched spur (the wall switch), before you check anything.
Scoop the water out with a cup and a sponge, then take out the filter at the bottom of the tub and rinse it under the tap. Put it back, locked properly in place.
Check the drain hose behind the machine (not squashed or kinked) and where it joins the waste pipe under the sink.

Stop: danger

Unplug the dishwasher before you put your hands in the tub or touch the pump cover. Water and electricity together are dangerous.
Water on the floor or a wet socket: don't touch the plug or socket. If the consumer unit (fuse box) is dry and you can reach it without standing in water, switch off that circuit. Then turn off the water supply to the dishwasher. If the consumer unit is wet, keep away and call 999.
Broken glass in the bottom of the tub: wear thick gloves to pick it out. Never use bare hands.

Where is it blocked?

What you see	Likely cause	What you can do
Dirty water and bits of food at the bottom	Blocked filter	Clean it, then refit it firmly
Water left after the machine was moved	Drain hose squashed or kinked	Straighten it and free it from behind the unit
The sink drains slowly too	Blocked sink waste pipe or trap	Clear the sink waste (bucket underneath)
Started just after a new sink or waste was fitted	The dishwasher connection may not be open or fitted properly	Ask whoever fitted it to check the connection
Humming with no draining, or an error code	Drain pump blocked (glass, fruit stones, labels) or faulty	Check your manual; otherwise, a repairer

Checking the drain pump (only if your manual allows it)

Unplug the dishwasher, take out the filter and scoop out the water.
Find the pump cover at the bottom of the tub. Your manual says whether you're allowed to remove it, and how.
Carefully take out anything you can see, such as stones, labels or bits of glass. Protect your fingers.
Put everything back, plug in and run a drain-only programme.

If you've lost the manual, you can usually download it from the manufacturer's website using the model number, which is often printed on the edge of the door.

What not to do

Pouring chemical drain unblocker into the tub: it can damage the seals and the pump.
Running cycle after cycle in the hope it clears: the pump can overheat.
Taking the machine apart beyond what the manual allows while it's still covered by your consumer rights or a warranty.

What you can do yourself, and where to stop

Yourself: scoop out the water, clean the filter, straighten the hose, clear the sink waste, remove anything you can see.
Call a repairer if the pump runs but doesn't drain, makes no sound at all, or if the dishwasher leaks onto the floor. With a built-in dishwasher, the hose can be hard to reach, so you may need a professional to check it.
Get a written quote showing parts and labour before any paid repair.

In England: if the dishwasher is faulty

Within 30 days of delivery, you can reject a faulty dishwasher for a refund. Within 6 months, the seller must repair or replace it unless they can prove it wasn't faulty when sold. You have up to 6 years to make a claim (5 in Scotland).
Go to the seller, not just the manufacturer. Citizens Advice explains how to return faulty goods: work through the questions on the page to find your options.
Recalls: search the GOV.UK product recalls and alerts list for your make and model.
Water through to a neighbour: tell your home insurer straight away, and your landlord if you rent.

Good to know

On some models, a little clean water stays at the very bottom, under the filter. Your manual will say whether that's normal for your machine. Dirty water sitting above the filter is the sign of a drainage problem.
Scrape plates before loading: fruit stones, bones and labels end up in the pump.
Clean the filter regularly, and always lock it back in place.
After moving house or having work done in the kitchen, check the hose isn't trapped behind the unit.

In Bristol, Priya keeps finding dirty water in her dishwasher, ever since a new sink was fitted. The filter is clean. Under the sink, the dishwasher hose looks badly connected to the new waste, so she asks the fitter to come back. Once it's connected properly, the machine drains again.

A made-up story, for illustration.

Bobby

Sources, verification, confidence

Verified on 6 November 2026, for England. Confidence: medium for the checks (consumer association guidance; always follow your own manual, especially for the pump); high for consumer rights (GOV.UK, Citizens Advice). This guide describes common cases, not a diagnosis.