[fastback4]

I get 28v at the furnace controller at the R and C (red & blue wire) posts. At the thermostat i get 8v at the R & C (red & blue) wires. White,Green & Yellow are 28v. Is this normal or is this bad....Regards......Tom

 

[SKIP4661]

Is the common {C} terminal on the thermostat wired to the furnace. 28v between R and W,Y,and G is normal if the stat is not calling for heat or cool or fan.

 

[fastback4]

The common C wire (blue) is wired to the furnace controller but not wired to the thermostat. I've been told this common blue wire will need to be used if i upgrade my thermostat to a programmable lcd readout type thermostat. Is this a fact?.........Tom

 

[Yoyizit]

http://www.hvacmechanic.com/tstatwiring.htm

Post a schematic of 'stat to furnace wiring. We will find the missing 20vac.