How to clean a tumble dryer filter, heat exchanger and water tank

In short: Clean the fluff filter after every load: pull it out, peel off the fluff, rinse it if needed and let it dry fully. On condenser and heat pump dryers, also empty the water tank every cycle and clean the heat exchanger as your maker says.

Co-authored by Sonia Abu Bakar✓, MSc Botany

By Abu Bakar Saadat7 min readPublisher: Saadat Rafiq

Last updated: 28 October 2026References

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At a glance

Fluff filter: After every load (Bosch, Samsung, fire services)
Water tank: Empty after every cycle on condenser and heat pump dryers (Bosch)
Heat exchanger: Every 2 weeks (Bosch condenser); at least monthly (Samsung heat pump)
Never: Run it while you sleep or are out (West Yorkshire and Cheshire FRS)
Advice from: Bosch UK, Samsung, West Yorkshire and Cheshire Fire and Rescue Services, read 28 October 2026
Checked: October 2026

A full fluff filter makes the dryer slower and is a fire risk: fire services ask you to clear it every time you use the machine (West Yorkshire and Cheshire Fire and Rescue Services). Condenser and heat pump dryers have two more jobs: the water tank and the heat exchanger. Steps 1 to 4 are for every dryer.

Which dryer do you have?

A hose goes out through a wall or window

Vented dryer. Do steps 1 to 4 and step 8. No water tank or heat exchanger.

A water tank, no hose; heat exchanger behind a flap at the bottom

Condenser dryer. Do steps 1 to 7. Bosch says to clean its filter and heat exchanger every two weeks.

A water tank, sold as "heat pump", often a reminder light

Heat pump dryer. Do steps 1 to 7. Samsung says to clean the heat exchanger at least once a month.

A washing machine that also dries

Washer-dryer. Samsung says its washer-dryers have no lint filter: the drain pump removes the lint, so clean the drain pump filter instead. Check your manual.

How to clean it

Careful: let the programme finish, including its cool-down (Cheshire FRS). Before you clean the heat exchanger, unplug the dryer (Samsung).

Let the dryer cool down, then switch it off.

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Stopping a dryer mid-cycle leaves the clothes hot, so let the full programme run, cool-down included, before you empty it (Cheshire FRS).

You should see: a dark display and a drum that is warm at most, not hot.
Pull out the fluff filter.

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Open the door. On Bosch dryers the filter sits behind and under the door (Bosch). On Samsung dryers you pull it upwards to remove it (Samsung). Bosch and Samsung filters come in two parts that separate.

You should see: a flat mesh filter with a layer of grey fluff on it, and an empty slot where it sat.
Open the filter, peel off the fluff and brush the mesh.

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Open the filter and take out the inner part if it has one (Samsung). Peel the fluff off both parts and put it in the bin. Bosch also says to remove fluff from the slot the filter sits in. Brush the mesh with the cleaning brush (Samsung).

If fluff is still stuck in the mesh, rinse both parts under running water (Bosch, Samsung).

You should see: mesh you can see light through, and no fluff in the slot.
Careful: don't run the dryer without the filter, or with the inner filter missing (Samsung).

Dry the filter completely, then put it back.

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Pat it dry with a cloth or paper towel (Bosch). If you rinsed it, let it dry fully first: Samsung says a wet filter can cause mould, bad smells and slower drying. Put the inner part back inside the outer one and slide the filter back into its slot (Samsung).

You should see: the filter sitting flush in its slot, and the door closing normally.
Empty the water tank (condenser and heat pump dryers).

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Bosch says to empty the tank after every cycle. Pull it out slowly and keep it level, pour the water into the sink and push the tank back in firmly. The water may be warm (Bosch).

You should see: the tank clicked fully home.
Careful: unplug the dryer first and don't touch the heat exchanger fins with bare hands: Samsung warns of burns and injury, and Bosch says the same about bare hands. Don't bend the fins (Samsung).

Open the flap at the bottom and clean the heat exchanger.

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Bosch condenser dryers: open the maintenance flap, release the levers and pull out the EasyClean filter. Wash and dry its mat by hand. Some heat exchangers can be taken out and rinsed with water; otherwise clean it with a soft brush (Bosch).

Samsung heat pump dryers: press the top of the outer cover at the bottom of the dryer to open it, unlock the levers on the inner cover and pull it out. Brush the fins with the supplied brush or a vacuum brush nozzle; if dust is dried on, mist it lightly with water first. Wipe the inner cover with a damp cloth, refit it and lock the levers (Samsung).

You should see: fins you can see between, with no grey felt across them, and both levers locked.
Wipe the moisture sensor inside the drum.

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The sensor, in the door area, tells the dryer when clothes are dry. Limescale or fabric conditioner on it can spoil the results. Bosch says to clean it with a coarse sponge, but never with abrasives or steel wool, which can damage it.

You should see: clean, shiny metal strips with no white film.
Vented dryers: check the hose and the outside flap.

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The vent hose should have no bends or blockages, and the flap on the outside vent should open while the dryer runs (West Yorkshire FRS). Cheshire FRS adds that the hose shouldn't be kinked or crushed.

You should see: a short, straight hose and the outside flap opening when the dryer is on.

How often, by part

Part	How often	Source
Fluff filter	After every load	Bosch, Samsung, West Yorkshire and Cheshire FRS
Water tank	After every cycle	Bosch
Condenser filter and heat exchanger	Every two weeks	Bosch
Heat pump heat exchanger	At least once a month	Samsung
Moisture sensor	No interval given; clean it if drying gets worse	Bosch
Vent hose	Check it is straight and clear	West Yorkshire and Cheshire FRS

How to tell it worked

The filter mesh is clear and the filter is back in place, dry.
The tank is empty and clicked in; no tank or filter warning is showing.
The next load dries in its usual time.
Clothes come out warm, not hotter than usual, with no burning smell.

If something goes wrong

What happens	What it means	What to do
Clothes still damp after a normal cycle	Blocked filter or heat exchanger, or an overloaded drum	Clean both (Samsung, Bosch) and dry smaller loads (West Yorkshire FRS)
Musty smell after cleaning	The filter went back wet (Samsung)	Take it out, dry it fully and refit it
Heat exchanger reminder won't go off	Some Samsung models show it after every cycle by design	Tap to dismiss; unplug and replug, or refit the inner cover (Samsung)
Water drops near the heat exchanger	Condensation; Samsung says this is normal and not a leak	Wipe it; check the tank is pushed fully in
Burning smell, or clothes hotter than usual	A fault	Stop using it and have it checked by a professional (Cheshire FRS)

Tumble dryer fire safety

Don't run the dryer while you are asleep or out of the house (West Yorkshire and Cheshire FRS).
Don't overload it: the clothes can overheat (West Yorkshire FRS).
Air-dry anything that has had oil, grease, fat or solvents on it: these can catch fire in the heat (West Yorkshire FRS).
Plug it straight into its own 13-amp socket, not into a socket shared with other big appliances (Cheshire FRS).
Stop using it if you see scorch marks or loose or damaged wires (West Yorkshire FRS).
Register it with the maker so you hear about recalls, and check for recalls on the Electrical Safety First website (Cheshire FRS).

A working smoke alarm matters too: see why a smoke alarm chirps and how to fix it. If you dry clothes indoors without a dryer, our guide to stopping condensation and mould explains how to keep the damp down.

Questions readers ask

Can I wash a tumble dryer filter with water?

Yes, on Bosch and Samsung dryers: both say you can rinse the filter under running water. Samsung says to let it dry completely before you put it back, because a wet filter can cause mould, smells and slower drying.

Why is my dryer taking so long to dry?

A clogged filter is the first thing to check: Samsung says skipping filter cleaning reduces drying performance. West Yorkshire Fire and Rescue Service adds that overloading slows drying and can be a fire risk. On condenser and heat pump dryers, also clean the heat exchanger.

The clean-filter light stays on after I cleaned it. Why?

On some Samsung heat pump dryers the heat exchanger reminder lights up after every cycle by design. Samsung says to tap the button to dismiss it; if it won't go, unplug and replug the dryer or take out and refit the inner cover.

Is it safe to run the dryer overnight?

Fire services say no. West Yorkshire and Cheshire Fire and Rescue Services both advise against starting a tumble dryer when you go to bed or leave the house.

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Sources

We use primary, official and specialist sources appropriate to the topic.

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