Have HVAC Questions? Ask an HVAC Expert for Answers
There are a couple of solutions for this.
How many wires do you currently have?
The options are as follows:
1.Run an extra wire
2.Sacrifice the FAN ON function of just being able to circulate air without heat or ac
3. Add an adapter in furnace that costs about 30 bucks.
Which of those sounds best to you?
Those are the only options except to get a thermostat that does not requires a C wire.