A tumble dryer that runs but blows cold air is usually a failed heating element or a tripped thermostat — and on heat-pump models often just a dirty filter or heat exchanger.
Likely causes, ranked
- Blocked lint filter or condenser Most likely — Restricted airflow makes the dryer cut the heat to protect itself. Clean the filter before every load; on condenser/heat-pump dryers clean the heat exchanger monthly.
- Failed heating element Likely — On vented and condenser dryers the element can burn out or one section can fail, giving long drying times or cold air.
- Tripped thermal cut-out / thermostat Likely — Overheating trips a one-shot thermostat; it needs replacing and the cause of the overheating (usually airflow) fixed too.
- Faulty NTC temperature sensor Less likely — A failed sensor can tell the control board to stop heating. Often shows as F03 (Hotpoint) or tE (Samsung).
First checks
- Unplug the dryer.
- Clean the lint filter thoroughly.
- On condenser/heat-pump models, remove and rinse the heat exchanger.
- Check the vent hose is not crushed or blocked (vented dryers).
- Run a short hot cycle and feel the air from the vent after 10 minutes.
Safety
Unplug before opening any panel. Heating parts hold high temperatures and, in some dryers, mains voltage — never test the element with the dryer plugged in.
Call a professional when…
The filter and exchanger are clean and the vent is clear but the dryer still blows cold — the element, thermostat or sensor needs an engineer.