Have HVAC Questions? Ask an HVAC Expert for Answers
Is this a new thermostat or did everything used to works as is?
Ok do you have a C wire providing voltage or are you relying on batteries? And have you replaced batteries?
OK do you have a heat pump ?
Does the outdoor unit come on when you call for heat?
OK remove front section of thermostat and tell me what wires are connected to what terminals.
OK remove wires and connect Red green and yellow wires together and tell me if outdoor comes on and if air blowing in house is hot or cold
Wires specified for now.
Did we get heat or ac?
Have to step away from desk for just a bit.Be back shortly. Did you leave the wires together?
You did not let anything touch the blue C wire did you?
OK if fuse blew you have a short in control circuit somewhere.
Red 1s 24v power.
Connecting red to green should energize fan relay
Connecting red and yellow should energize contactor in outdoor unit.
Perhaps a wire touched c while removing .Look in air handler a small 3 amp auto type fuse.
is fuse blown?
OK do you have a meter to check between R and C at thermostat for 24 volts?
You may have to get a meter next or call in a tech to see why we get nothing at thermostat
Best bet is going to be to grab a phone book and look for local heating and ac contractors to find nearest one .I am not from the area so not familiar with local companies.