The Furnace Works indoor wood boiler SFB-3

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J.Grant907

New Member
Nov 12, 2017
3
Virginia
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Hello,
I am looking for any information on the the Furnace Works indoor wood boiler SFB-3. I have one installed im just trying to wire it up properly. It is currently set up to be used in conjunction with my main propane boiler which is controlled by a Honeywell L8148E high limit only Auqastat. The wood boiler has a L6006 low limit controller on it which has a 14/2 wire going to the main boiler which is not wired up. The other end of the low limit is tied into the damper control of the wood boiler. Also Im not sure if the plumbing is correct or not as for how it is tied into the main boiler. Any information would be helpful.

Thanks
Jgrant907
 
I likely won't be much help - but it's hard to tell what's going on there.

I don't see a damper control on the wood boiler? Its aquastat should just need power from a 120v source, don't think it would need to go through the oil controls. Also looks like dangling wires from its circulator? Something should be controlling that - circulating wood boiler water when it gets to setpoint. Also not sure what that third circ up high does?
 
Owned a SFB 120 back around 1980 , the only thing the aquastat on the boiler controlled was the was the draft , the circulator was controlled by the thermostat .
 
I likely won't be much help - but it's hard to tell what's going on there.

I don't see a damper control on the wood boiler? Its aquastat should just need power from a 120v source, don't think it would need to go through the oil controls. Also looks like dangling wires from its circulator? Something should be controlling that - circulating wood boiler water when it gets to setpoint. Also not sure what that third circ up high does?

The damper control is at the bottom right of the door the red and white wire on the aquastat are running down to the damper. Yes i haven't connected the circulating pump yet. It is run of the high limit auqastat on the propane boiler. I wasn't sure if the circ pump on the wood boiler would be controlled to keep the main boiler at temp and or also circ the main line when the thermostat calls for heat. The third circ pump was to an old twin flo fan/ rad because the removed the radiator from the kitchen during a rebuild before we owned rhe house.
 
I am thinking the wood circ should simply be controlled so it keeps the oil boiler at temp. Then the oil boiler can just go about its business sending heat to the house, and the burner will cut in as normal if the wood fire goes out. Which should also mean that it should be controlled so it will shut off if the wood fire goes out and wood boiler goes cold. Low limit? I have an 8124 doing my controlling. But I simply pulled it off my old wood/oil boiler and moved it over to the new system - so don't exactly have full knowledge of aquastatish things. You could maybe use a different controller that will start that circ whenever the wood is up to temp, and stop it when it drops - all controlled by sensing wood boiler temp. Maybe a Johnson A419?

That's a really inefficient wood boiler BTW - I'm sure Hobbyheater could fill you in on that if he cares to. :)
 
Yes that is how i would like it to operate. My main circulating pump failed on the propane boiler. The house is from 1925 w/ old school radiators. So to replace the pump there is a possibility of having to drain the system because original owner never installed any shut off valve. Im not sure if the vents or shut off valves on the radiators work either.
So i connected the circ pump for the wood stove and have been using it ro circulate for the last day or so.

You had mentioned that the SFB-3 probably isnt real efficient, with i had kinda figured with its age,but it will be cheaper than the amount of propane ive been using. Plus I have been able to get my hands on some free wood.
 
Ye


You had mentioned that the SFB-3 probably isnt real efficient, with i had kinda figured with its age,but it will be cheaper than the amount of propane ive been using. Plus I have been able to get my hands on some free wood.

One thing to watch is the butterfly of the draft that it does not build up with creosote and stay partly open .