Wireing a thermostat to control blower and bypass valve

[woodturner2]

Hi,I have a lennox downflo oil furnace. I have just installed a water to air heat exchanger from my outdoor wood boiler under the furnace. I have a Taco 560 3 way bypass valve in the line so i can bypass the heat exchanger and keep heating my DHW. I would like to hook this up so I can use the air exchanger as my main heat source and have oil backup. I have a Honeywell RTH7400 thermostat. Can i use this thermostat or do I need a different one? Can someone tell me how to wire this up?
Thanks, Greg

 

[RJP Electric]

you want to control your oil or wood interdependently, the easiest way is to use 2 thermostats. here is a simple diagram. you must use a separate 24 volt transformer for zone valves or you will burn them out.

Bob

 

[woodturner2]

I was told I have the wrong valve I need one without the 120 volt side.

 

[RJP Electric]

I relabeled the drawing, that 120 volt side is an extra transformer you are going to need to buy.