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Electric Radiator Won't Turn Off
Your electric radiator stays on constantly and will not respond to the thermostat or controls.
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What's happening?
An electric radiator that will not turn off is running continuously regardless of the thermostat setting or room temperature. This wastes energy, can overheat the room, and may indicate a fault that could become a safety issue if left unchecked.
What usually causes it?
- Thermostat has failed in the closed (on) position
- Relay or contactor stuck in the on position
- Electronic control board fault keeping the element energised
- Wiring error bypassing the thermostat
- Faulty room sensor giving a false low-temperature reading
Is it dangerous?
A radiator that will not turn off is a moderate concern. While most radiators have a thermal safety cutout to prevent overheating, continuous running wastes energy and puts unnecessary strain on the element. In a room with poor ventilation, it could also cause the room to become uncomfortably or dangerously hot.
Can I fix it myself?
Turn the thermostat to the lowest setting or to the off position. If the radiator continues to run, the thermostat has likely failed. For plug-in models, unplug it. For hardwired models, switch off the isolator or fused spur until an electrician can attend.
When should you call an electrician?
Call an electrician if the radiator does not respond to the thermostat or controls, if switching it off requires isolating the circuit, or if the radiator is getting excessively hot. This is not an emergency but should be addressed promptly.
What will the electrician actually do?
- Test the thermostat to confirm it has failed
- Check the relay or contactor for sticking
- Test the electronic control board
- Replace the faulty thermostat, relay, or control board
- Test the repaired unit to confirm it cycles correctly
What will it cost to fix?
£80–£200
Thermostat and relay replacements are straightforward. Control board replacements depend on the model and parts availability.
Find an electricianFrequently asked questions
We’re happy to answer all your questions.
Why won't my electric radiator turn off?
The thermostat or relay has most likely failed in the on position. This is a common fault with older radiators and usually requires replacing the thermostat or control unit.
Is it safe to leave a radiator running constantly?
Most radiators have a thermal safety cutout, but continuous running is not ideal. It wastes energy and puts strain on the element. Isolate the radiator and call an electrician.
Can I just use a plug-in timer as a workaround?
A plug-in timer can provide temporary control for portable radiators, but it does not fix the underlying fault. The thermostat should be repaired or replaced for proper temperature control.
Sources & References
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