How to Test a Baseboard Heater's Thermal Cutoff Switch

Similar to dryers, some baseboard heaters use a thermal cutoff switch. This switch cuts off power to the heater in the event the temperature becomes too hot. This is often due to a bad thermostat. If your baseboard heater is not turning on and heating as it should, it might be a bad thermostat or possibly a bad thermal cutoff switch. Testing a baseboard heater's thermal cutoff switch requires removing the switch from the unit.

Phillips screwdriver
Multimeter

Instructions

- 1
  Turn off the circuit breaker to the baseboard heater. Baseboard heaters use high voltage and will cause shocks.
- 2
  Pull the temperature knob off the baseboard heater. The knob simply locks onto the temperature shaft and pulls off with slight force.
- 3
  Remove the screw securing the thermostat cover with a Phillips screwdriver. The screw is usually near the bottom of the cover. Lift the bottom of the cover away from the baseboard heater and pull it down to remove it from the unit.
- 4
  Unhook the two wires connected to the thermal cutoff switch. The thermal cutoff switch is next to the thermostat shaft and is usually about 2 inches long. Pull the thermal switch out of the baseboard heater.
- 5
  Set your multimeter to the lowest Ohms setting. Touch the two probes of the meter together and adjust the meter dial so the scale reads zero.
- 6
  Touch one probe to one of the thermal cutoff terminals and the second probe to the remaining terminal. The scale should read zero ohms. If it does not, the thermal cutoff requires replacement.

How to Repair an Eighteen-Volt Ridgid Reciprocating Saw

How to Remove the Line or Hose From a Whirlpool Dual Water Valve

Appliance Repair