US Stove furnace parallel wiring help

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here
Status
Not open for further replies.

TCNC

Member
Hearth Supporter
Nov 29, 2007
22
Central, NY
The manual isn't very helpful with the wiring for a parallel installation. I have an electrician (after he talked to US Stove) saying a parallel installation won't work without the optional draft kit (backorder until dec.), but every manual I see for US Stoves and other similar add ons talk about installing parallel and don't mention needing the induced draft to function.

The draft kit may be a good idea at some point to have greater control of the fire, but I don't want to wait until December for it. In the meantime, I want the furnace wired so that the two small blowers come on when the wood furnace gets up to temp., and for them to blow the air into my oil furnace plenum and once the temp in the plenum reaches a certain temp, for my main furnace fan to kick on. Is this possible? Thanks.
 
What model, on most of these forced draft is a joke. It pushes air above the fire, and you burn more wood than needed. Secondly, they are made to control the 2 blowers on the back from the thermodisc, or limit control from the wood furnace. Did you buy it used? You can go online and get a manual for the furnace to tell you how to wire those. The recommended way to install these from the factory is a parallel installation. In order to do this, you need a backdraft damper below the lines to keep the woodfurnace from backfeeding into the man furnace.
 
Thanks for the reply! I take it this means I do not need the induced draft kit to hook this up parallel to my oil furnace? It's a 1537 and brand new. The manual refers to a "figure 13" on page 13 for wiring, but there's no figure 13 in the manual. I talked to US Stove and they sent me a wiring diagram for their smaller wood furnace with the single blower. I've attached what they sent me. Is the combination control is this diagram the fan & limit control in my oil furnace? My oil furnace is only 2 years old and if I open the front of it, that control is right there.

I hate to pull the dumb girl card, but if you could explain simply what wiring from the wood furnace connects to what on my oil furnace, I'll be so thankful. Don't worry, I'm not going to wire it myself (unless I can't convince these men they're wrong!), but if I understand it, I can pass it on and be convincing. :) My understanding right now is that the wood furnace will start its blowers when the thermodisc tells them to which will blow the heat from the wood furnace jacket into the oil furnace plenum. My oil furnace will then kick its fan on when the temperature in the plenum gets to a certain point and help push the heated air through the ducts, right?

We put in a damper/baffle made from ducting sheet metal to keep the oil furnace's air from backflowing into the wood furnace. Are you saying I need another one of those in the plenum to do the same for the oil furnace? Can I ask where you put that in the plenum and if you bought or made it?

Thank you, thank you, thank you.




laynes69 said:
What model, on most of these forced draft is a joke. It pushes air above the fire, and you burn more wood than needed. Secondly, they are made to control the 2 blowers on the back from the thermodisc, or limit control from the wood furnace. Did you buy it used? You can go online and get a manual for the furnace to tell you how to wire those. The recommended way to install these from the factory is a parallel installation. In order to do this, you need a backdraft damper below the lines to keep the woodfurnace from backfeeding into the man furnace.
 

Attachments

  • [Hearth.com] US Stove furnace parallel wiring help
    furnace 001.webp
    74.8 KB · Views: 1,627
Nicole,
I have a similiar stove. I agree that the induction kit might be a waste of money on these units. When I tried that setup using the fans from the wood furnace and the main furnace, the main furnace overpowered the wood furnace so the heated air wouldn't escape the wood furnace, but I didn't have any baffles. I would first try running your wood furnace blowers to see if you can get airflow out of your vents without using your main furnace blowers to assist, and for this you should have the baffle to keep the warm air from the wood furnace from going into the main furnace. If all the fans do work well together, one way to wire it would be using a 24 volt transformer. Leave your wood furnace blower wires as-is running the black and white wire from the blowers into the transformer which will send power to the transformer when the wood furnace blowers come on. Ground the 24V negative wire from the transformer to the main furnace and hook the 24V positive wire into the G (Fan Only) on the main furnace. I'm sure there's other ways, including the use of a relay, but this is what I did when I was testing different installations and it worked well. If all 3 fans are coming on together, I would't think it would backfeed into your main furnace even without a baffle.
 
Status
Not open for further replies.