12-27-2021 01:29 PM
I replaced my Honeywell digital thermostat with a Google nest. There are white, yellow, red, green, and blue (common wire). I have properly wired my Google nest, but for some reason is saying that I do not have power to the C wire. First of all, there is a C wire connected, and I have verified that it is connected to the C wire on the control board on the HVAC unit. Help??
12-27-2021 08:05 PM
Best thing to do at this point is to get a basic multimeter and check the voltage between R and C at the thermostat terminals. You're looking for approximately 24v AC. Most furnace control boards have a separate fuse just for the 24v circuit. Mine is an automotive type fuse - easily pulled and replaced.