Tumble dryer not heating up? Causes and fixes you can test

This article contains affiliate links: if you buy through them, Wanda-techs earns a commission at no extra cost to you.

Your tumble dryer is not heating up: the drum turns, but the clothes come out damp or the cycle never seems to end. Most of the time the air is not flowing properly because of a blocked lint filter, a clogged condenser, a full water tank or an overloaded drum.

Work through the fixes in order. The first ones need no tools.

Common symptoms and causes

• The drum turns, but the air stays cold.
• The dryer no longer dries properly: clothes are damp at the end of the cycle, or drying takes far longer than it used to.
• A filter, condenser or water tank light comes on.
• The lint filter or condenser is clogged, or the water tank is full.
• The drum is overloaded, or the programme you chose does not use heat.
• The vent hose is blocked, or the room is too cold or too hot.
• The moisture sensor (the part that decides when the laundry is dry) is covered in limescale.
• A part has failed: thermal fuse, heating element, thermostat or, on a heat pump model, the refrigerant circuit.

Before you start

Warning: unplug the appliance from the mains before opening anything. Never work on a dryer that is plugged in. The capacitors in some appliances stay charged after unplugging: do not touch them.

Warning: after a cycle, the drum and the heat exchanger are hot. Turn the selector to OFF and let the dryer cool down before cleaning anything.

Warning: opening the appliance can void the warranty, and so can a lack of basic maintenance. Check when your warranty ends first. The heating element, thermostat and thermal fuse are a job for a repairer.

Keep the manual and the model number handy. Also work out which type of dryer you have: condenser, heat pump or vented.

Solution 1: check the programme and the load

1. Check the programme you selected. According to a summary of Samsung’s support pages, which we could not verify on the page itself, cold-air programmes such as Air or Air Fluff do not heat.
2. Take out some laundry if the drum is full. An overload restricts airflow, so the air heats poorly.
3. Stay within the maximum load given for the programme in the manual.
4. Do not mix different types of fabric in the same cycle.
5. Spread the laundry evenly in the drum, then restart the drying.

The laundry should come out dry in roughly the time announced. Laundry that was not spun well enough probably lengthens drying too, although none of the sources we read confirms it. If your machine spins poorly, see our guide on a washing machine that won’t spin.

Solution 2: clean the lint filter

1. Turn the selector to OFF and wait for the appliance to cool down.
2. Open the door and pull the filter upwards to remove it.
3. Open the filter with its catch to reach both parts.
4. Remove the lint from both parts with a damp hand, or with a vacuum cleaner if it sticks.
5. On a Bosch, rinse the filter under running water or put it in the dishwasher.
6. Hold the filter up to a lamp: a clean filter lets the light through. If it is torn or warped, replace it with a genuine part.
7. Remove the lint from the filter housing and the door seal.
8. Check that no lint has fallen into the duct.
9. Put the filter back.

The filter lets the light through. Air flows again.

Tip: Electrolux recommends cleaning this filter after every cycle. It is the habit that prevents most endless drying cycles.

Solution 3: empty the water tank and clean the condenser

Warning: on a heat pump dryer, Bosch advises against cleaning the heat exchanger yourself. Follow your model’s manual or contact customer service. If your condenser is self-cleaning (the AutoClean function at Bosch), leave it alone too.

1. Empty the condensation water tank: when full, it stops the next drying cycle.
2. Slide the tank back in until it clicks.
3. Remove the removable heat exchanger (the condenser).
4. Rinse the exchanger with water on all sides, seals included, without any hard or sharp object.
5. Let it drain thoroughly.
6. Put the exchanger back and lock it.
7. Clean the stainless steel moisture sensors with the rough side of a sponge to remove limescale and detergent residue. Their location is in the manual.

Drying returns to a normal length and the laundry comes out dry. A clogged condenser lengthens drying and makes it less efficient: Bosch advises cleaning it about once a month, depending on use.

Tip: empty the tank after every cycle, as Bosch recommends. The next drying cycle will no longer stop halfway.

Good to know: manufacturers do not agree on the method. Bosch has you rinse the exchanger with water, whereas Samsung, according to the information available, advises against water, brushes and vacuum cleaners on its models that show the Clean Heat Exchanger alert. Your model’s manual has the final say.

According to an excerpt from Whirlpool’s support pages, which we could not read in full, the FILTER light on some models stays on after 5 cycles. Switch the appliance off with ON/OFF, unplug it, clean the filter and the condenser, then plug it back in. The light should go out on the next cycle.

Solution 4: clear the vent and ventilate the room

Good to know: the first three points come from Samsung, Bosch and Electrolux pages that we could not all verify in full.

1. On a vented model, check that the hose is neither kinked nor blocked.
2. Clear the appliance’s air outlet, especially on a heat pump model.
3. Keep the appliance’s air inlets clear.
4. Check the room temperature. Bosch recommends between 15 and 30 °C (59 to 86 °F), and to avoid anything below 0 °C (32 °F) or above 35 °C (95 °F).
5. In a small, poorly ventilated room, open a window or the door while the dryer runs.

The air leaves freely and the cycle returns to its usual length.

If the hose on your vented model is crushed, pierced or too short, here is an extendable 102 mm hose to check against the diameter of your outlet.

Wpro extendable PVC exhaust hose for tumble dryers, 102 mm, up to 3 m

Carries the humid air of a vented tumble dryer outside. It stretches to fit the distance to the outlet.

• AmazonSee at Amazon

According to a summary of Electrolux’s support pages, its dryers work in a room between 5 and 35 °C. The range therefore differs from one brand to another.

If nothing works

Filter, exchanger, tank and duct are clean, the room is mild, and there is still no heat? Stop there. A blown thermal fuse cuts the heating and has to be replaced by a professional, according to Samsung.

On a heat pump model, no heat with a clean filter and exchanger points to the refrigerant circuit. That is a technician’s job.

Electrolux describes a heating test, which we could not read on its page: run a timed cycle of at least 120 minutes with an empty drum, open the door after an hour and check whether the drum is hot.

Before you call the manufacturer’s customer service or a repairer, note down:

• the model number and the product number (PNC at Electrolux), printed on the rating plate around the loading opening;
• the symptoms, the error codes and the lights that are on.

The same drying fault exists on other appliances, such as a dishwasher that won’t dry.

If the appliance is old and the repair costs more than it is worth, here are three heat pump dryers from well-known brands to compare.

Take better care of your tumble dryer: our toolbox

A few accessories to keep the air flowing and make maintenance easier.

Frequently asked questions

Why does my tumble dryer spin but not heat up?

Most often the air is not flowing properly: blocked lint filter, clogged condenser, full tank or overloaded drum. Also check that the programme is not a cold-air one. If everything is clean and the air stays cold, a part such as the thermal fuse, the heating element or the thermostat is at fault: call a repairer.

How do I clean the condenser of a tumble dryer?

On a Bosch, take out the removable heat exchanger, rinse it with water on all sides, let it drain, then put it back and lock it. Samsung recommends a different method on some models. On a heat pump model or a self-cleaning condenser, leave it alone: follow the manual or contact customer service.

My heat pump dryer no longer dries: what should I do?

Clean the lint filter on the door and clear the appliance’s air outlet. Bosch advises against cleaning the heat exchanger of these models yourself: follow the manual or contact customer service. If the filter and exchanger are clean and the dryer still does not heat, the refrigerant circuit is at fault and needs a technician.

When should I call a repairer for a tumble dryer?

When it still does not heat with a clean filter, condenser, tank and duct. The heating element, thermostat, thermal fuse and the circuit of a heat pump cannot be repaired by yourself. Have the model number, the symptoms, the codes and the lights shown ready.