Heat exchanger in furnace - Fan only to run on call for heat

[Wood-row Wilson]

I'm looking to install a heat exchanger in my pole barn furnace plenum, also where my Garn Jr. is, and I'm looking to get the furnace to only run the fan on a call for heat. Now, I don't have gas hooked up to the furnace, so when I tie the thermostat wires together and flip the switch, my pilot tries to light the gas (funny, it tries to work like a furnace should...). From my understanding, the furnace is waiting for the gas flame to get up to temp before it kicks on the fan.

How do I circumvent this? I'm hoping to be able to get a programmable thermostat to keep the pole barn just above freezing or schedule to get up to heat by the time I plan to use it. Of course, I can run the blower wires directly to the switch, but this takes away my ability to use a thermostat to control the fan!

Heaterman provided the instruction and diagram for making this work on my house furnace, so I'm wondering if that will help? I've attached this, and also attached is a picture of my control board on the pole barn furnace. I've been harassing him enough, so I'm hoping to see if there is a quick way to accomplish this that others have experienced before.



What do I need to make this work? The furnace is an older Bryant and I can't for the life of me find a model number.

Thanks for your help!

 

[fire245]

I'm looking to install a heat exchanger in my pole barn furnace plenum, also where my Garn Jr. is, and I'm looking to get the furnace to only run the fan on a call for heat. Now, I don't have gas hooked up to the furnace, so when I tie the thermostat wires together and flip the switch, my pilot tries to light the gas (funny, it tries to work like a furnace should...). From my understanding, the furnace is waiting for the gas flame to get up to temp before it kicks on the fan.

How do I circumvent this? I'm hoping to be able to get a programmable thermostat to keep the pole barn just above freezing or schedule to get up to heat by the time I plan to use it. Of course, I can run the blower wires directly to the switch, but this takes away my ability to use a thermostat to control the fan!

Heaterman provided the instruction and diagram for making this work on my house furnace, so I'm wondering if that will help? I've attached this, and also attached is a picture of my control board on the pole barn furnace. I've been harassing him enough, so I'm hoping to see if there is a quick way to accomplish this that others have experienced before.

View attachment 149058 View attachment 149059

What do I need to make this work? The furnace is an older Bryant and I can't for the life of me find a model number.

Thanks for your help!

The Green and Red are the fan only leads. Marked RH and G. Thay are a simple switch loop. Rh has 24 volts and G is wire directly to the low voltage fan relay. RH may be jumped to RC which in your case is OK. Wire rh to rh on thermostat and G to W on the tt. this way when your set point is reached your fan will come on. send me pictures if you have more questions. Kc master electrician

 

[marty53]

Hey there-- I have a setup like this in my house. I run two thermostats, one control the regular oil burner on the furnace, the second for the wood boiler runs into one of these honeywell fan controls: http://www.supplyhouse.com/White-Rodgers-90-113-Fan-Control-Center-120-VAC-Primary-24-VAC-Secondary-SPDT-Relay-14874000-p

So the blower is wired seperately right into this fan control (and the wood furnace thermostat), and from the main oil burner. I keep my oil thermostat at 55.

 

[heaterman]

Are you using the gas section of the pole barn furnace at all or will you be strictly using the Garn as the heat source?

If Garn only and no gas involved simply move the wire on the furnace from W to G.

If you want the furnace to run gas or Garn, you'll need another strap on aquastat like that L6006.