Find the disconnect switch to your air handler or furnace, and switch it off. This will be located near the unit. Shut off the circuit breaker at your home’s electrical panel if you can’t find the ...

I have since removed the Honeywell RLV3120A 2-wire thermostat and put back in the old mechanical twist-knob thermostat. Since this one has three wires I connected the black and red to the same two ...

Lexie is a former Staff Writer at Forbes Home and has over 6 years of professional experience as a writer and editor in the home improvement space. She's previously worked at sites such as HomeAdvisor ...