If washes come out cold on a hot programme, the heater, its temperature sensor, or the board's heater circuit has failed — this needs an engineer.
Likely causes, ranked
- Failed heater element Most likely — Limescale burnout is common in hard-water areas.
- Faulty thermistor Likely — The temperature sensor stops reporting, so the board never switches the heater on.
- Heater relay or board fault Less likely — The board cannot switch the heater circuit.
First checks
- Confirm you are running a hot programme (Cottons 40/60), not an eco or cold programme.
- Feel the door glass mid-cycle — it should be warm on a hot wash.
- Note any error code shown (F03/F15/H3/H1/H2 are common heater codes).
Safety
Do not open the machine — heater circuits are live. Unplug before checking the door glass area.
Call a professional when…
Always call a professional for heater faults — all likely causes are inside the machine on live circuits.