Dishwasher Not Draining Properly: Quick Fixes for Standing Water

It's a disheartening discovery: you open the dishwasher expecting sparkling clean dishes, only to be met with a pool of greasy, stagnant water. The good news is that a dishwasher not draining properly is often caused by a simple blockage you can fix yourself, like a clogged filter or a kinked drain hose.

Leaving it can quickly lead to foul odours, dishes that are dirtier than when they went in, and even potential water damage to your kitchen floor.

Before you panic, it’s worth knowing what you're up against. We see this issue all the time, and it usually boils down to just a handful of culprits.

Common Causes of Dishwasher Drainage Failure

As you can see, most frequent causes are things you can resolve without needing an engineer. Familiarising yourself with these common dishwasher faults and their solutions can save you time and hassle.

Now, let's figure out what's stopping that water from draining.

Quick Fixes You Can Perform in Minutes

Before you book a repair, there are simple checks you can do. More often than not, the reason your dishwasher is not draining properly is something you can sort out in a few minutes.

The most common culprit is a blocked filter. It’s designed to catch food and grime, but it doesn't take much for it to get clogged and stop water from escaping.

In fact, neglected filters are behind an estimated 55% of all drainage issues. You’ll find the filter at the bottom of the dishwasher’s tub—just twist it to unlock. A good rinse under a hot tap is usually enough to clear it. If it’s stubborn, our guide has tips on the easy steps to cleaning your dishwasher filter properly.

Another quick thing to look at is the drain hose. Pull the machine out slightly and check for any obvious kinks or tight bends in the hose, as this can easily stop water from draining.

A YouGov survey revealed that only 16% of Britons feel confident enough to repair their own dishwashers. However, these simple checks are perfectly safe and can save you the cost of a call-out.

Inspecting the Drain Hose and Sump Pump

So, you've cleaned the filter and there's still a puddle of murky water. Don't worry, this usually means the blockage is just a bit further along the line. Your next port of call should be the drain hose and the sump area, as a clog here is often why your dishwasher is not draining properly.

Often, the problem isn't inside the dishwasher itself. If your machine's waste pipe connects to your sink's plumbing, a backed-up garbage disposal system can stop water from draining. Look under your sink, find where the dishwasher hose connects, and pop a bucket underneath. Carefully detach the hose and check for blockages.

If the hose is clear, the culprit might be in the sump at the bottom of the dishwasher tub. You'll need to bail out any standing water first. Then, grab a torch and look inside the sump for anything that shouldn't be there – we often find things like broken glass, pips, or small bones.

If you find a tough blockage, you may need to use a specialised dishwasher drain unblocker to dissolve the build-up.

If you’ve worked through all potential blockages and your dishwasher still won’t drain, it’s time to consider a mechanical issue. Drainage problems make up 25-30% of all appliance service calls we see. This is a huge number, and you can see the wider trend across the UK on Ibis World.

The Drain Pump and Float Switch

More often than not, the problem lies with the drain pump. A tell-tale sign of a failing pump is a distinct humming or grinding noise when the drain cycle should be running, but no water is being pumped out.

Another potential issue is the float switch, a safety device that tells the dishwasher when to drain. If it gets stuck due to debris, it will never signal the pump to start.

Tackling these internal components yourself isn't recommended. Both the pump and the float switch involve electrical connections and are best left to a qualified engineer.

When to Call a Go Assist Engineer

It’s great to be hands-on, but it’s also important to know when to stop. Pushing a DIY fix too far can turn a straightforward repair into a bigger, more expensive problem.

If you’ve worked through the common fixes but there’s still a puddle of murky water, or you’re hearing a nasty grinding sound, it’s time to call an expert. Messing with the dishwasher’s motor or electrical parts can risk water damage or create a safety hazard.

Booking a Go Assist engineer is the simplest, safest way forward. Our trusted technicians know all major brands and can sort most drainage problems in a single visit.

Leaving a drainage issue won't make it go away. In 2022, London homeowners spent an estimated £3.24 billion replacing appliances that could have been fixed. What starts as a simple blockage can escalate into water damage costing over £500 to fix. You can find more UK appliance repair statistics and insights here.

Don't let a small issue become a major headache. If you're out of your depth, visit our Dishwasher Repair page and let our engineers handle it.

Common Questions Answered

Here are our quick answers to some of the most common questions we hear from customers.

Is It Normal to Have a Little Water at the Bottom of My Dishwasher?

Yes, a small cupful of clean water in the sump is normal for most models. This water helps keep the internal seals from drying out. What isn't normal is a murky, smelly puddle covering the entire floor of the tub. If that’s what you’re seeing, you have a drainage problem.

Can I Just Run Another Cycle to Force It to Drain?

Please don't. Running another cycle just adds more water into a machine that can't get rid of what's already there, risking an overflow and water damage. Some machines have a ‘drain only’ setting, which is a much safer bet. Otherwise, find and clear the blockage before starting another wash.

How Much Will a Professional Dishwasher Repair Cost?

While the price depends on the fault, a professional repair is almost always more cost-effective than buying a new dishwasher. More importantly, a proper repair avoids the risk of making things worse with a DIY attempt, which could cost you more in the long run.

If you’ve tried the simple fixes and that stubborn water still isn't budging, don’t risk a flood. The expert engineers at Go Assist can pinpoint the problem and get your dishwasher draining again in no time. Book your fixed-price repair online today.