The short answer
Clean the filter first because it is free. After that, on a machine of this age suspect the rubber: a perished drain hose that collapses under suction, then a non-return flap hardened out of shape. A jammed pump impeller is third. Intermittent draining points at the hose and flap rather than at the pump.
What you observe
- It drains on some cycles and not on others — Aged rubber behaving differently each time.
- Dirty water appears in the tub between cycles — The non-return flap is not seating.
- The pump runs steadily and nothing leaves — A hose collapsed or narrowed along its run.
- A hum from the pump with no movement at all — The impeller is jammed by something hard.
- NEAR MISS — a film of water over the filter — Normal. It keeps the seals from drying out.
Causes, most likely first on this brand
- Drain hose perished, narrowed or collapsing — First on a machine of this age because the hose is original rubber that has lost both its bore and its stiffness. It closes under the pump's own suction, which is exactly why the fault comes and goes.
- Non-return flap hardened out of shape — Second: hardened shut it blocks the outflow, hardened open it lets waste water siphon back into the tub between cycles. Both look like a pump problem and neither is.
- Filter assembly loaded or no longer seating — Third, and the cheapest to rule out: a filter whose seal has stiffened lets debris past into the pump instead of holding it where you can rinse it away.
- Pump impeller jammed or the pump failing — Last. A hum with no movement names a jam, and a silent pump with a clear hose points at the motor, which is a repair-or-replace decision at this age.
Check in this order, and why
- Twist out the filter and rinse it — Free, and it rules out the simplest cause.
- Note whether the fault is intermittent — Coming and going points at aged rubber.
- Pull the machine out and feel along the drain hose — A soft or flattened section is the answer.
- Look for dirty water returning between cycles — Left until here because it names the non-return flap.
What an owner can safely check
- Bail the sump, twist out the filter and rinse it — Clear both screens and lock the assembly back in.
Tools: jug, spongeAbout 25 min
- Run a drain programme and listen underneath — Note whether the pump hums, runs, or does nothing.
About 20 min
- Switch off, pull the machine out and inspect the hose — Feel its whole length for soft, flattened or crushed sections.
Tools: torchAbout 40 min
- Check the tub after a completed cycle for returning water — Water appearing later points at the non-return flap.
About 20 min
- STOP HERE if the pump hums and shifts nothing — Clearing the impeller means opening the machine.
Before you open anything
Safety
Unplug the machine or switch off its breaker before reaching into the sump or moving it; a capacitor can hold a charge after the power is off. Broken glass is common in a blocked sump, so wear gloves and look before you reach. Never run the machine with the filter removed, and take care pulling an integrated machine out past the worktop and the furniture door.
When to call a technician
Call when the filter is clean, the hose is sound along its whole run and the machine still holds its water — the non-return valve or the pump is then the answer and both are inside the cabinet. Ask for the pump price before agreeing, because at this age it often approaches a replacement. Call a plumber instead if the sink waste itself is slow.
Nearest pages of this class
What this page does not cover
This page is written for the brand and the appliance class, not for one family or model line. Where a family- or model-specific page exists for your unit, that page is the more specific answer and you should start there. Deliberately absent: hose diameters, pump and valve part identifiers, waste spigot sizes and fault-code meanings, all of which differ between the integrated, freestanding and slimline families.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
