Asked on Feb 21, 2012

Installing a programmable thermostat for electric baseboard heaters.

KMS Woodworks


We currently have two 240 v baseboard heaters in our master bedroom, attached to one old double pole thermostat. Want to replace it with a programmable. Bought a honeywell off amazon for use with electric baseboard, but it throws the breakers (heaters are on a double breaker). Maybe it can't handle two heaters together? In the wall we have two sets of wires (each set has a black and a white - I assume one for the heater and one to the power source). Any advice is appreciated!!
1 answer
  • KMS Woodworks
    on Feb 21, 2012

    All 240 volt systems will be on a "double" is the TOTAL voltage differential. 240 s use a hot / hot type configuration as apposed to a normal 120 that use a hot / neutral config. The critical issue is to pair the right breaker "rating" with the appliance...and unsure the wiring is up to snuff. My big project yesterday was upgrading the wiring for a 240 volt steam shower. This was modified recently and some 12 ga wire was used...this was set up with a 15 a /240 breaker. This steam generator requires 10 ga with a 30 a breaker. You will need to check the power rating of the thremo...and see it it matches the combined loads of the heaters...normal limits for 12 ga are only 20a.

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