I am in the process of installing an outdoor wood burner, Central Boiler, and hope that someone could give some advice on installing the thermostat. I currently have fuel oil forced air in my house. The thermostat controlling that furnace is a round honeywell. The wiring is a two wire (red and white) wrapped in brown coating. I have to install a second thermostat to turn the fan on in my current furnace to circulate the water from the wood burner through the new coil in my forced air furnace plenum. I don't want the second thermostat to turn on the forced air furnace burner - just the fan. Which terminals in the furnace do I hook to to do this. Which terminals at the new thermostat do I hook to also. I already tried talking with Central Boiler and their individual there told me to refer to their technical manual from the dealer. Their manual shows how to hook the new thermostat to the current thermostat when the current thermostat is being operated with three wires. Mine is only being operated by two wires and I am not able to re-wire my current thermostat to three wire. Thank you

If the book says you need three wires,, you need three wires. You need to find a way to get that third wire and then wire it as stated in the instruction manual..

You have already spent quite a bit of money for the purchase of the system. So I say spend a little more and have a tech that is familiar with these systems come out to take care of the final touches.

See page 3 for Add a wire. There are also other manufactures that make a product similar.

http://www.venstar.com/Support/Manuals/ACC0410ManualRev1.pdf

I am doing the same set up. Forced hot air (nat'l gas) and central boiler. I connected a second thermostat in series w/ the Auto/On switch and left the switch in the ON posistion. I found out that leaving it in the Auto position will energize the AC if energizing the fan only