Convert wood boiler to wood/electric

[FrankL]

Not even sure this is possible, and will it work? But... I have a wood boiler with a hot water coil insert. Do you know of any way to replace the hot water coil (it bolts on,) with an electric heating element? We don't use the hot H2O coil, anyway. The wood boiler is rated at 70, 000 Btu.. If the changeover works, I'm guessing I won't have to change much else, other than a bigger expansion tank and a few controls, maybe... Thanks for your help! (Upstate NY Frank)

 

[brenndatomu]

Just install an electric boiler inline...easy peasy. Gonna need plenty of extra capacity in your breaker panel for electric heat though...and it'll make your meter spin like a top, hope this is just for backup!

 

[peakbagger]

I agree, far better off using a new hot water heater than trying to convert a wood boiler into one. Way too much mass in a wood boiler and compared to a hot water heater far poored insulation.

 

[maple1]

As said, get an electric boiler instead. But it will cost an arm and a leg to operate, if you operate it much. Unless you have a really low heat load/loss, and low temp emitters. Even then, it will be costly.

 

[FrankL]

As said, get an electric boiler instead. But it will cost an arm and a leg to operate, if you operate it much. Unless you have a really low heat load/loss, and low temp emitters. Even then, it will be costly.

Thanks for all the answers out there. A number of things influencing what I'm thinking about: the price of oil last winter (through the roof! upstate NY); we have been blessed with some solar panels, and room for more; I'm gettin' up in years to be handling firewood; the Marathon Logwood boiler we have has only a 25 gal water jacket--I suppose I could wrap it a bit more with rock wool, unfaced; one-story, 10-year old ranch style house with R-25 wall and R-50 ceiling insulation. House holds the heat well, once it reaches temperature. Radiators operate independently of boiler temperature. (But, this whole thing may still be a crazy idea! )

 

[peakbagger]

No matter how tight a wood boiler is, there will be air flow up the stack. A boielr is sdesigned to exchange heat between a heated interior where the fire is to exterior water jacket. When you heat up the water jacket some large portion of the heat inside the jacket will end up going up the stack.

 

[maple1]

Thanks for all the answers out there. A number of things influencing what I'm thinking about: the price of oil last winter (through the roof! upstate NY); we have been blessed with some solar panels, and room for more; I'm gettin' up in years to be handling firewood; the Marathon Logwood boiler we have has only a 25 gal water jacket--I suppose I could wrap it a bit more with rock wool, unfaced; one-story, 10-year old ranch style house with R-25 wall and R-50 ceiling insulation. House holds the heat well, once it reaches temperature. Radiators operate independently of boiler temperature. (But, this whole thing may still be a crazy idea! )

I considered an element option with my gasser in 2012 when we got rid of our oil. But just got a used electric boiler instead, for cheap, for backup. But I haven't used it at all since we put our mini splits in, 3 years ago. And our wood use went way down since they cover shoulder season, and they also do AC in the summer. If I was going to make further changes to our hydronic system, it would involve changing or adding different rads. To something low temp like cast iron rads or panel rads. Then add an A- W heat pump once that tech develops a little further. Both oil and electric resistance are expensive to operate. But that can be reduced somewhat with low temp emitters. If you have them. After a good building envelope, low temp emitters are the next factor in reducing hydronic energy costs.

 

[FrankL]

No matter how tight a wood boiler is, there will be air flow up the stack. A boielr is sdesigned to exchange heat between a heated interior where the fire is to exterior water jacket. When you heat up the water jacket some large portion of the heat inside the jacket will end up going up the stack.

Thank you. Hmmn. Good Point. Even with the vents tightly closed I'm guessing there will be heat loss going up the chimney due to thermal circulation. (Heat wants to go to where it's cold, and the outside air coming down the chimney will be cold....) Maybe my idea wasn't such a great one, after all... 8-(

 

[FrankL]

I considered an element option with my gasser in 2012 when we got rid of our oil. But just got a used electric boiler instead, for cheap, for backup. But I haven't used it at all since we put our mini splits in, 3 years ago. And our wood use went way down since they cover shoulder season, and they also do AC in the summer. If I was going to make further changes to our hydronic system, it would involve changing or adding different rads. To something low temp like cast iron rads or panel rads. Then add an A- W heat pump once that tech develops a little further. Both oil and electric resistance are expensive to operate. But that can be reduced somewhat with low temp emitters. If you have them. After a good building envelope, low temp emitters are the next factor in reducing hydronic energy costs.

Thank you, I appreciate your good advice... Just trying to make things easier for my wife when I "kick the bucket," as we used to say in the country! She and I have been burning wood for 45 years (more, if you add in when I was a boy back on the farm,) and we're getting too old to be manhandling (or womanhandling) firewood....