Hello all
I just built a plenum around my coal stove and I need to wire in a stat , limit switch to run a blower fan . Thanks Steve PS I have all the parts off and hot air oil furnace.

Usually there is a 24 volt AC transformer in the furnace with the secondary winding connected to a red wire running to the thermostat and a blue wire, common, to the gas valve, A/C relay, and fan relay. From the thermostat there will be white wire to the gas valve, yellow to the A/C, and green to the fan. The thermostat is wired to switch the power from the red to the white, yellow, and green as needed with the blue completing the circuit. Most thermostats and furnaces have the contacts labeled R, B or C, W, Y, and G for the corresponding wire colors.

What are you going to do, just blow air over the coal stove and out into the room? Even if you are going to direct it into the existing ducts, the air around the stove is already going to be warm which is what the one limit switch does. The second limit switch shuts off the oil if things over heat. I doubt you can shut off the coal fire. So all you really need to do is to run the white wire from the thermostat and blue wire from the transformer to the coil of the blower relay.

Hello Labman

I completely incased the stove witch started life as a Large Boss woodburner until I made it a coal stove 3 yrs ago. I had a plenum on top with a small 6 in. booster fan coming from my cold air return and a pipe going to my oil furnace plenum.100 degrees in the basement and barely moving air up stairs. This year I built a new plenum incasing the stove except the load and exhaust side airtight. I welded 8 vertical 3x3 capped tubes on top of the stove airtight.I am running an 8 in. feed from the return to a furnace blower blowind air under and around the stove out the top with 4 six in. pipes to my oil furnace plenum. I have a Honeywell oil furnace controller with a coil in it and a place to hook the stat wires with a limit switch in the plenum. Can I use this setup. I also added a domestic hot water tank to preheat my electric tank. My wife says I think too much lol. Thanks Steve

Like I said, the oil furnace should have had a relay for the blower. Just wire the white wire from the thermostat to the relay coil. You need another wire back to the transformer to complete the circuit. If you mount the limit switch in the plenum where is it warm, it should stay closed.

Thanks for the info Labman. Steve :)

How to wire a blower for a wood stove with thermostat on fan for forced heat