Blocked Dishwasher Filter: What Cleaning Fixes and What It Hides in Knowle

The filter sits at the lowest point of the tub and does the job your sink strainer does: it stops food, fat and debris reaching the pump. When it loads up, water cannot leave the tub properly, the wash water gets dirty and recirculated, and the machine starts to smell. Most of that is reversible with a clean.

What a blocked filter looks like

• water pooling in the base of the tub between cycles
• a greasy film on the dishes and glasses after a wash
• a sour or drains smell inside the machine
• cloudy glasses that were previously clear
• the machine completing a cycle but leaving debris on plates

None of those are dramatic, which is why a blocked filter often goes unaddressed for a long time. The machine keeps running, just badly.

Cleaning it properly

The filter assembly usually lifts out in two or three pieces: a coarse basket, a fine mesh cylinder and sometimes a flat plate. Rinse each under a warm tap and use a soft brush on the mesh. Do not use a wire brush, which opens the mesh and lets debris through. Warm water and washing-up liquid are enough; a dishwasher cleaner run afterwards will help with fat inside the tub and the sump.

While the filter is out, look into the sump. You should see the pump impeller housing cover, not a pool of greasy water and food. If there is standing water there, the drain path is restricted and the filter alone will not fix it.

Also check the spray arm jets, because debris that bypassed the filter often ends up there, and a partly blocked arm sprays unevenly.

What a blocked filter can hide

This is the part worth being honest about. A machine run for a long period with a restricted filter has been working harder and washing in dirty water. Two things can follow:

• The drain pump has been strained. It may still run but weaken, or it may have collected debris that a clean will not shift.
• The wash pump and heater have been running in dirty water. Scale and fat can build on the heater, reducing its efficiency.

So a clean may restore normal operation, or it may reveal that a component has already suffered. We cannot tell you which until the filter is out and the machine is run.

When it is more than a clean

If the machine still will not drain after a proper clean, the blockage is downstream: the hose, the sink spigot or the trap. If it drains but does not clean, the spray arms or the wash pump are the next suspects. If it drains and cleans but smells, the tub and sump need attention rather than the filter.

Safety and scope

Cleaning the filter is a user task and safe with the machine switched off. Anything beyond that, including removing the sump cover or the pump, is our work. Where the job requires it, water and power are isolated first, and only where that can be done safely. If there is water around the base of the machine or near the plug, leave it off and tell us.

Do not put the filter parts in a dishwasher cycle to clean them, and do not run the machine without the filter fitted, because debris will go straight into the pump.

Aftercare

After a clean, run a hot cycle with a dishwasher cleaner, then check the filter weekly for the first month to see how quickly it loads. If it fills again within a fortnight, something in your routine is sending a lot of debris down: scraping plates properly and rinsing less than you think is usually the answer.

Booking

If you have cleaned the filter and the machine is still not right, that is the point to book. Tell us the brand and model, what you have already cleaned, and what the machine does now. Book online, pay the booking fee when you book, and the hourly labour rate depends on how soon you need the visit. The full cost is quoted and approved before work begins.