Electric Underfloor Heating Not Working
Check the steps below first — if you're not confident, get it fixed safely today.
Post a job — we'll find you an engineer →Do not attempt to repair the heating mat or cable under tiles — this requires a qualified electrician. Only the thermostat and circuit checks below are DIY-safe.
Electric underfloor heating (UFH) uses a heating mat or cable embedded in the floor. Problems are almost always either a failed thermostat, a tripped circuit, or (less commonly) a break in the heating element. The first two are easily checked at home; a broken element requires an electrician.
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Most likely cause & what to check
Go to your consumer unit (fuse box) and check whether the circuit breaker or RCD for the underfloor heating has tripped. If so, reset it. If it trips again immediately, there is a fault in the wiring or element — call an electrician.
Check the thermostat. Ensure it is switched on, the setpoint is above the current floor temperature shown, and the display is illuminated. If the thermostat is blank, check whether it has its own fuse in the fused spur on the wall.
Check the floor sensor — most electric UFH thermostats have a small temperature probe that sits between tiles to measure floor temperature. If this probe has failed or broken, the thermostat will either not activate or will show an error code (E1, E2, etc. depending on brand). Sensor replacement is usually DIY-friendly (£10–30).
If the thermostat shows a floor sensor error code, you can bypass the sensor temporarily — check your thermostat manual for how to switch from floor-sensor mode to air-sensor mode. If the heating works in air-sensor mode, the floor probe has failed.
If the thermostat appears to be working (its output light is on) but no heat is coming from the floor, the heating element itself may have failed. An electrician can test the element resistance with a multimeter — a reading significantly different from the value on the element's label indicates a failed element.
Heating mat or cable replacement requires lifting tiles or flooring and is a significant job (£400–1500 depending on area). Get quotes from 2–3 electricians before committing.
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