How to check a faulty electric heater

Tools: –   a screwdriver

–   a voltmeter.


1/ connect the radiator to the mains, switch to the Comfort or ON or I position and turn the thermostat button to the Max position. If the radiator does not heat check the fuse or circuit breaker of the supply line. If heater still does not operate, disconnect it from the mains

2/ using a volt-meter, check that the wall connection box receives the electricity.

3/ open the radiator and check all wires, ensuring that all connections are firmly tightened

If discovering any incorrect connection, re-connect the heater to the mains and check again.


4/ check the heating element, the thermal safety cut-out, and the On/Off switch if any:

  • disconnect each element
  • adjust to the Ohm position on the voltmeter
  • apply each pin of the voltmeter to both ends of the contacts of the following components : heating element, thermal safety cut-out and On/Off button (if any)
  • result :   –   if the current goes through, the component is OK

–   if the current does not go through, the component is faulty

5/ In case the heating safety cut-out and On/Off button (if any) are ok but the heater still does not operate, replace the electronic thermostat

NB: if heater is operated through a programmer, checking should be made after having disconnected the heater from the programmer (position button should be on the Comfort position)


When ordering spare parts, please note carefully the indication of the identity plate of the heater and indicate in your request:


  • full reference number
  • power
  • date of manufacturing     (for instance : 2045 = 20th week of the year 2005)