Tumble dryer runs but clothes are still damp

1. Blocked door lint filter

   Most likely

   The filter needs clearing every single load. Even a thin even film cuts airflow enough to double drying time, and fabric softener leaves an invisible waxy coating that needs washing off under a tap every few months.

   How to check: Hold the filter up and run a tap over it. If water pools rather than passing straight through, it is coated and needs scrubbing.

2. Clogged heat-pump evaporator filter

   Most likely

   Heat-pump dryers have a second, much finer filter behind a flap in the base, in front of the heat exchanger. It clogs invisibly and is the single most common cause of poor drying on these machines. Many owners have never opened it.

   How to check: Open the lower flap on the front of the machine and look at the sponge or mesh filter behind it.

   Heat-pump evaporator filter£12–£35 for the partDIY

3. Full water tank or blocked condensate drain

   Common

   A full tank stops the cycle or prevents the machine condensing properly. On a plumbed machine, a blocked condensate drain does the same.

4. Blocked vent hose

   Common

   On a vented dryer, a crushed or lint-packed hose stops moist air leaving. The machine gets hot and the clothes stay wet.

5. Overloading

   Common

   A drum packed too full leaves no room for air to move through the load. Dryers need roughly half to two-thirds of the drum free to work.

6. Failed heating element or thermostat

   Occasional

   The element fails, or a thermal cut-out trips because airflow was restricted. Note that the cut-out is usually a symptom of a blockage rather than the root cause — replacing it without clearing the airflow just trips it again.

   Thermostat / TOC kit£10–£30 for the partEngineer

1. 1

   Clean the door filter properly

   Pull the lint off, then hold the filter under a running tap. If water sits on the mesh instead of flowing through, scrub it with washing-up liquid and a brush to strip the fabric-softener film, then dry it fully before refitting.

   10 minWashing-up brush
2. 2

   Open the lower flap and clean the second filter

   On a condenser or heat-pump dryer, open the flap in the bottom front of the machine. Remove the condenser block or sponge filter and rinse it under a tap until the water runs clear. Let it drain fully before refitting.

   20 min
3. 3

   Empty the water tank and check the drain

   Empty the tank in the door or lid. If the machine is plumbed to a waste, check that hose is not kinked or blocked.

   5 min
4. 4

   Check the vent hose on a vented dryer

   Detach the hose and check it is clear along its whole length and not crushed behind the machine. Clear the wall vent too.

   15 min
5. 5

   Halve the load and run again

   Dry a small load and see whether it comes out dry. If it does, the machine is fine and was simply overloaded.

   60 min
6. 6

   If it runs cold, get it looked at

   A dryer that tumbles with no heat at all after all filters are clear needs an engineer to test the element and thermostats. Mention that you have already cleared the airflow — it stops them replacing a cut-out that would only trip again.

   10 min

Is there an error code on the display?

If your tumble dryer is showing a code, that will narrow the diagnosis a lot further than symptoms alone.