Appliances
Washing machine won’t drain? Check the filter first
A drum full of grey water and a door that refuses to open is one of the most common washing machine faults, and one of the cheapest to fix. Most of the time the answer is sitting in the coin trap, along with 40p and a hair grip. Here is the order to check things in.
By the Tickover team · Published 5 June 2026 · 4 min read
What is going on inside
At the bottom of every machine sits a small drain pump, and in front of it a filter, better known as the coin trap. Its whole job is to catch coins, buttons, bra wires and stray socks before they reach the pump. When the trap clogs, the water has nowhere to go, and the door interlock stays locked while the drum is full.
Listen at the point in the cycle where it should drain. A steady hum means the pump is trying to work against a blockage. Silence, with the rest of the machine alive, points at the pump itself.
The coin trap ritual
One thing nobody tells you: every drop of water in that drum is about to come out of a hole near the floor. This is a ten-minute job, but only if you set up for the flood before you open anything.
Clear the coin trap
Unplug the machine
Water and electricity share this job, so the plug comes out before anything else. If the drum is brimming, scoop what you can into a bucket first.
Towels down, tray ready
The trap hides behind the kick-panel flap at the bottom front. Lay old towels and wedge a shallow tray, a roasting tin works, under the flap.
Drain it slowly
Many machines have a small drain-down hose clipped beside the filter; unclip it and let it trickle into the tray. No hose? Turn the filter half a turn and let water seep past. Empty the tray, repeat, be patient.
Unscrew the trap fully
Anticlockwise until it comes free. Expect one last rush of water as it clears the housing.
Clear it and check the impeller
Fish out the coins, grit and the sock. Reach gently into the housing: the pump impeller at the back should spin freely under a fingertip.
Refit and run a rinse cycle
Screw the trap back in hand-tight, plug in and run a short rinse. Watch the flap for drips; a cross-threaded trap leaks impressively.
Trap clear? Check the exits
If the trap was clean, follow the water. Pull the machine forward and look at the drain hose: machines pushed hard against the wall kink their own hose, and the fix is thirty seconds of repositioning.
Where the hose joins the kitchen sink waste, there is a spigot on the trap that clogs with fat and food over time, and on new installs the blanking plug inside it is sometimes never cut out at all. If the sink side looks suspect, the blocked sink guide covers cleaning that trap properly.
Why won’t it drain?
When it is the pump, and what that costs
A clear trap, a clear hose and a machine that still will not drain means the pump or its controls have failed. That repair lives behind the casing, and the casing is not your territory: unplugging and clearing the trap is homeowner work, opening the machine up is not.
Pump failure, priced
Drain pump replaced
typical single-fault repair
New mid-range machine
for comparison
Typical UK ranges, mid-2026, as a guide only. Your home, your area and the job itself all move the number — always compare real quotes.
Whether the repair is worth it depends almost entirely on age. A pump on a three-year-old machine is an easy yes; the same quote at year eleven deserves the maths in the repair or replace guide before you commit.
Not sure it’s the trap?
Self-Diagnose in the Tickover app walks your machine’s symptoms through a few questions and tells you the likely fault, how urgent it is, and what an engineer will need to know before quoting.
While the flap is open, put a note in the calendar to do this again in a few months. Stagnant water in the trap is also one of the reasons a machine starts to smell, so the same five minutes solves two problems.
Quick answers
Why is my washing machine door locked with water inside?
The interlock refuses to release while the drum holds water, which is the machine protecting your floor. Unplug it, then drain through the coin trap or the small drain-down hose at the bottom front. Once the water is gone the door releases. Forcing the handle tends to break the handle, not the lock.
How often should I clean the washing machine filter?
Every two to three months is a sensible rhythm, and sooner if draining slows or you regularly wash things that shed, like pet bedding and heavy towels. Households with children tend to feed the trap faster, because it is where pocket contents end up. Five minutes of cleaning prevents most drainage call-outs.
Can a sock really get stuck inside a washing machine?
Yes. Small items of laundry can slip past the door seal at the top of the drum, especially in overloaded washes, and work their way down into the sump below. They then sit near the pump inlet until they block it. Check the coin trap before assuming the pump itself has failed.
How much does a washing machine drain pump cost to replace?
As a rough guide, a drain pump replacement lands in the £90 to £180 band that covers most single-fault washing machine repairs, fitted. Whether that is money well spent depends on age: an easy yes on a machine a few years old, much harder to justify near the end of the typical 8 to 12 year lifespan.
This guide is general information for UK homes, not advice about your specific property. Anything involving gas must be done by a Gas Safe registered engineer, and notifiable electrical work by a qualified electrician. If you smell gas, call the National Gas Emergency line on 0800 111 999. If you’re ever unsure, stop and get a professional in — that’s exactly what Tickover is for.
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