Back from a long hiatus from hearth !! Need recommendations on oil wood combo ?!

[Seacoastnhwoodburner]

I used to use this forum/page daily when I was burning 24/7 with my old vigilant ! .... I wasn’t able to recover my password for my old account, it’s been several years .Fast forward to today , we are in the process of adding on to our home !! New home will be 3000sq feet , brand new chimney to be built to spec , I’m sitting on close to 20 cords of three year old seasoned wood split and ready to go . I will always have a steady supply of wood , I understand that with combo the unit it is not as efficient as using two separate units . My question is ,what combo oil wood boiler , do you guys recommend? I primarily want use oil , and use wood on weekends and time when I’m home during the winter ! Thanks in advance!!

 

[TCaldwell]

You might investigate a switzer boiler, I believe the business name is switzer custom wood burning, Gary is in Dundee ny. This is a gasification wood boiler, storage incorporated with a oil gun as well. Several members here have one, as well as build, Gary installs also.

 

[Seacoastnhwoodburner]

Thank you ! From my initial research on line , I have really only found two manufacturers! Benjamin and tarm .

 

[maple1]

Take Benjamin off your list.

I'm not really aware of any combos that do it really well. Wood Gun has an oil add on option. Unsure of others.

 

[Bad LP]

Thank you ! From my initial research on line , I have really only found two manufacturers! Benjamin and tarm .

To my knowledge Tarm doesn't make them anymore and hasn't for a while.

 

[Fred61]

Biomass offers a combo boiler although I wouldn't recommend that set-up following my experience with the Wood Gun. As wired from the factory the unit would activate the oil burner when the boiler temperature dropped to a set point. Sounds good don't it? However if the boiler cools because the fire didn't re-light soon after idle because there was only a small spark left to re-light the oil could activate and would bring the boiler temperature up to the set point on the wood aquastat and would therefore do the same cycle of dropping to the oil setpoint and repeat as many times until I got home to re-light the wood in the chamber.
So my fix was to build a circuit to lock the oil burner into oil mode which was a step in the right direction. Only problem is that the oil side was so inefficient I could watch the fuel gauge drop before my eyes. Oil would still activate at the cooler setpoint so I would be heating all that mass with oil. You could say "raise the oil setpoint" but then you would run into the cooling of the boiler on re-start from idle and start heating with oil when there was still an ample amount of wood in the chamber.
The irony of it was I would usually get home just in time to see that the oil burner has burned three gallons of oil to bring the boiler back up to temperature.
I must admit that there were a few issues with my installation. I was pretty much a pioneer since this was in the early 80's.

 

[Seacoastnhwoodburner]

Biomass offers a combo boiler although I wouldn't recommend that set-up following my experience with the Wood Gun. As wired from the factory the unit would activate the oil burner when the boiler temperature dropped to a set point. Sounds good don't it? However if the boiler cools because the fire didn't re-light soon after idle because there was only a small spark left to re-light the oil could activate and would bring the boiler temperature up to the set point on the wood aquastat and would therefore do the same cycle of dropping to the oil setpoint and repeat as many times until I got home to re-light the wood in the chamber.
So my fix was to build a circuit to lock the oil burner into oil mode which was a step in the right direction. Only problem is that the oil side was so inefficient I could watch the fuel gauge drop before my eyes. Oil would still activate at the cooler setpoint so I would be heating all that mass with oil. You could say "raise the oil setpoint" but then you would run into the cooling of the boiler on re-start from idle and start heating with oil when there was still an ample amount of wood in the chamber.
The irony of it was I would usually get home just in time to see that the oil burner has burned three gallons of oil to bring the boiler back up to temperature.
I must admit that there were a few issues with my installation. I was pretty much a pioneer since this was in the early 80's.

 

[Seacoastnhwoodburner]

Thank you all for the advice! I’m glad to be back on the hearth bandwagon ! For what it’s worth , like I said I will primarily be using oil 75% of the time .. and wood on the weekends , time off from and power outages . I think a lot of the problems come from doing the opposite?? ... from all my research wood gun looks like the best ! I’ve read many negative reviews about the Benjamin unit . Also free wood is never a problem . So I would still like go ahead with a combo unit !

 

[maple1]

I would not do a combo.

If I was burning oil 75% of the time I would be wanting to do it efficiently. Which would likely mean a low mass multi pass cold start boiler.

 

[Seacoastnhwoodburner]

I would not do a combo.

If I was burning oil 75% of the time I would be wanting to do it efficiently. Which would likely mean a low mass multi pass cold start boiler.

 

[Fred61]

from all my research wood gun looks like the best ! I’ve read many negative reviews about the Benjamin unit . Also free wood is never a problem . So I would still like go ahead with a combo unit !

If you want to spend some time on this site, check out my contributions on the Wood Gun. I wouldn't install one if it was given to me along with a bucket of cash.

 

[E Yoder]

I would agree with maple1, a separate oil or gas boiler with a gasification wood boiler tied to it with appropriate controls would be much more efficient.

 

[maple1]

Along with a new efficient oil boiler, I would likely just add in a real good wood stove to supplement with & for power outage situations. And not do a wood boiler. Unless you can go whole-hog and get a gasifier, and one of those won't work optimally without storage. So then you get into more complex system design and maybe space concerns - and likely a considerably larger budget than you have been thinking of.

Could do an outdoor gasifier like a Heatmaster G, but estimating only 25% heat from wood seems to me to make anything other than a simple (but good) wood stove not pencil out, $$ wise, at all.

 

[brenndatomu]

Along with a new efficient oil boiler, I would likely just add in a real good wood stove to supplement with & for power outage situations

This ^ ^ ^
At 75% oil, you will be sorry you went the combo route by the end of the first winter...my Yukon combo wood oil furnace is coming out this summer...