My first post in the boiler room. Wood/Oil combo furnace

[daveswoodhauler]

OK, been on the forum for a while with our wood insert, so this is my first post in the boiler section.
Basically, I am looking for info on if anyone here has a combo wood/oil boiler? and how it works for them?
I know, I know, I said the oil word....but in my situation we would need to have a combo type unit, but I have heard that they are not too efficient. (Might be mis information on my part)
So, here is my situation...have about 1800 Sq feet (2 story colonial built in 1999), oil furnace with coil for dhw. I use about 500 gallons of oil/year and burn appx 1 1/2 cords of wood.
The reason that I was looking at a wood boiler, is that I work from home 3 days/week so I would be home to load the boiler with wood, and on days I am not at home we could use the oil.
Trying to determine the cost factors, as I get my wood for $175/cord...mainly beech/oak/maple, and I stack for 2 years before burning.
The other reason I was looking at a wood/oil unit, is that we are looking to finish our basement, and I was wondering if the furnace when running on wood would radiate the heat like a wood stove? (Sorry if this is a dumb question)
Really, I am just looking for some basic info on how folks like these type units, and wondering typical wood usage/daily reloading, etc...
Hope this is in the right forum.
Thanks

 

[willworkforwood]

A friend of mine has been running an Eshland Woodgun wood/oil combo for around 25 years, and it has worked out very well for him. But he burns wood whenever possible, so the OB quality is much less important to him. I don't know how efficient his OB is - I've heard they don't give you a good one, but I don't know that for certain. You don't mention if your primary objective is to save $$. If so, I think your payback at 175/cord would be quite a few years, especially if you would be using oil so often. Many (most ?) of the folks here with Gassers get their wood for small money, and run it whenever possible. In my case it's a combination of my own land and scrounging, so my 12K total boiler investment will be paid back this (fourth) year. There are some Woodgun owners on the forum, and perhaps they will be more helpful regarding the quality of the OB. Personally, given the situation you described, I wouldn't do it - but that's just me.

 

[woodsmaster]

Sounds like if you go with a boiler you need some storage to use while your gone and you could charge it when your at home. Why not use the oil boiler you have and add a wood gasser to the systym. It would require two flus so maybe thats not an option ?

 

[muncybob]

If I could have run 2 units I would have but the cost of installing a 2nd flu was too much, hence the combo we have now. We hardly use the oil side...still using oil that's been in the tank 2+ years, although we are ordering 125 gal.(min order here) just to have on hand for weekends we are not home, etc.

Since we don't use oil much I cannot make a statement on the efficiency but I would venture a guess that it's mo worse off than the old Axeman oil boiler that the WG replaced....and that was running at maybe 50% efficiency. As mentioned, wood at $175/cord will indeed take a number of year to break even on the cost.

The WG could be insulated better. Our basement is easily 70*+ in the winter and heat migrates upward to the living room.

 

[laynes69]

Are you looking at a boiler or furnace? I seen both in your post and wondered. 1800 sq ft isn't alot of space to heat. If you have ductwork in place then a furnace would be a good option. There are models that are EPA certified also. Our woodfurnace keeps our basement warm without any sort of vents in the basement, just comes from the radiant heat from the glass window on the door.

 

[daveswoodhauler]

Thanks folks. We have a boiler (forced hot water)...so based on the info here and my cost of wood, I''m guessing that the wood furnace would not be the way to go. I was just thinking that based on the btus of wood compared to oil the cost makes sense to burn wood, but based on the cost of the boiler and mechanicals I would be a very long payback. I guess I just love burning wood..hence me looking into the possibility of a wood boiler. Current setup is chimney with 2 flues....one for the oil burner, and one for the insert in the living room. Was looking at the TARM units, but after looking at the pricing I am thinking the payback is going to be a very long time for us if we went to a wood/oil combo unit.
Again, much thanks for the replys, as I have a much better understanding of the systems now.

 

[maple1]

If I could have run 2 units I would have but the cost of installing a 2nd flu was too much, hence the combo we have now. We hardly use the oil side...still using oil that's been in the tank 2+ years, although we are ordering 125 gal.(min order here) just to have on hand for weekends we are not home, etc.

Since we don't use oil much I cannot make a statement on the efficiency but I would venture a guess that it's mo worse off than the old Axeman oil boiler that the WG replaced....and that was running at maybe 50% efficiency. As mentioned, wood at $175/cord will indeed take a number of year to break even on the cost.

The WG could be insulated better. Our basement is easily 70*+ in the winter and heat migrates upward to the living room.

What do you do for DHW in the summer? I'm also considering a woodgun with an oil burner for heat backup & DHW in the non-heating season, but it doesn't look like it is the most efficient setup for that with the coil on top & burner on bottom. Plus the comments about it not being the best insulated. I'm not happy with my current combination unit, but one thing they did to right with it is put the DHW coils right above the oil chamber, at least as far as DHW only burning goes.

 

[muncybob]

I installed an electric hot water heater for the non burning season. If I were to burn wood for dhw I think we would probably have storage of some type so the fire ony happens every few days. I can tell you that we never have a problem with dhw supply when burning wood....hot and plenty of it!

 

[maple1]

Yes, I was assuming the wood gun would give lots of hot water when burning wood. My current furnace is oil/wood, and we just run the oil burner in the summer for hot water (and winter for backup when we're not home & the wood fire goes out). Not the most efficient way to go, having to keep the boiler hot all summer with oil just for DHW, but it is easy & simple - just costs more than it likely should. And I'm not sure it is any more running that than a separate electric water heater would be anyway - I'm guessing it's costing us around $700/year in oil for DHW in the off season with the combo unit. I think if I went with the wood gun (still researching the options), I would check out being able to tie in some solar panels to help keep it warm during the summer. Would really be curious to hear how much oil is being burned for DHW in the summer by someone with a wood gun using an oil burner in it for that purpose.

 

[muncybob]

Our average electric bill went up about $15 to $20/month after heater install. We are usually just a 2 person household but 2 to 4 showers/day. I've read that oil is about the most expensive option for DHW unless you have a very high efficient boiler and a well insulated one at that!

Our electric bill always is more expensive in the winter so really the total bill amount never varies much since we shut down the electric heater in the winter.

 

[maple1]

$15-20? That sounds pretty good. From asking around here, I was thinking we'd be over $50 anyway, maybe pushing $100. Three growing kids though, and all the showers & laundry that comes with that.

 

[infinitymike]

hey guys,
Can I chime in?
I am getting my WG S.S. E100 on Thursday

Believe it or not I never considered using the oil burner.
WHY you ask? Well I don't really know.
Seems like everybody here hooks up in series or parallel with there existing OB.
So I thought I would too.

But I'm starting to have second thoughts.

I have on old oil burner made by Ford. There is no other label on it so i don't know the btu output or how old it is.
Its probably super inefficient. Besides the house being insulated like a wiffle ball.
I use about 1000 gallons of oil on a 1800 ft 1 1/2 story expanded ranch on LONG ISLAND.

I have no storage for DHW. I don't know how big the coil is but it struggles to supply enough hot water for a shower in the dead of winter.

I want to add storage for DHW for the WG.

I have no idea how to plumb this yet.
I would assume that if I rip my old OB out completely, that the plumbing would be cheaper,
since I'm not tying into it.

Any thoughts.

 

[maple1]

This is a good thread.

I plan to replace my old current wood/oil combo boiler with SOMETHING that includes gasification, and I need a second heat source for backup and for DHW in summer, with solar panels a likely addition. I had been mostly thinking all along that for the best efficiency it would be 2 units, a wood burner and an oil burner. The more reading I do, the more choices I find, and the more my head spins - and I am thinking single unit again. So now I am considering a wood gun, and putting my current burner in it (Riello). That would likely be the simplest solution, but likely not the most efficient over all. Then there is the Varmebaronen CU model with electric backup. I had not considered anything using electric before, but the oil would not get used much at all during the winter - therefore the electric wouldn't either - and it has a DHW tank built in, and gasses wood with natural draft (but then I would have a Riello burner collecting dust). Natural draft is a very attractive feature to me with our power outages - plus it should use quite a bit less electricity with no induction fan to run all winter. And I could do away with everything oil related and the associated risks (oil tank leaks) and gain basement space. If money was no object, I would likely put in a Buderus oil unit & water tank, and a gassification furnace, with storage and 6 or 8 solar panels. Or I guess just stop at the Buderus and keep the oil truck coming back if I had that much money.

infinitymike, I would seriously consider doing away with your old furnace (if it's that old), and putting an oil burner in the wood gun. That should clean up your whole system and gain you a whole bunch of space - and would only require one chimney connection (I think). Even though the wood gun looks like it might not be the most efficient unit to heat DHW with just oil, you should still be ahead. You could even light a fire every few days and not burn much oil at all, especially with a storage tank added. We use most of our hot water here on the weekends (laundry & extra showers), so a Friday night or Saturday morning burn would go a long way to cutting back on oil use. Is your oil burner itself a decent one, or is it as old as the furnace?

 

[Gasifier]

DAVESWOODHAULER.

Have you considered looking for a used wood/oil boiler combination. I have seen some H.S. Tarm units that were for sale. Sometimes people did not want to burn the wood anymore, someone bought a house and does not want the work that comes with wood and is updating to newer, more efficient boiler. Etc., Etc. With a used one you may be able to make up that payback and still have the joy of burning wood. I always keep in mind what else burning wood does for us. Gives us piece of mind. Any day next week, next month, or next year oil prices could sky rocket. Think 3.75/gallon is bad. Imagine if sometime it went to 5.75/gallon. There are so many factors around the world that could effect the price of it. The biggest being greed. But with wars, storms, evil doers, etc., etc. you never know.

It may take you some work if you buy a used one. But there is nothing like a good project. Here is a used one I found searching google. You may want to watch craigslist, ebay, etc.
[email protected]

Just a thought. Take your time, if you are not in a rush you may find a good deal some day. Don't give up burning wood. In my opinion, the security and piece of mind of burning wood can not be overstated.

Here is another. Check this one out. Go to craigslist and look at pictures, not bad.

HS Tarm combination oil & wood Boiler (Rutland)

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Date: 2011-09-26, 10:37PM EDT
Reply to: see below [Errors when replying to ads?]
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HS Tarm combination oil & wood 120,000 BTU 10" 13" fire door
10" wide 21" deep 30" tall
dommestic hot water tank
$1650.00
Please call 802-342-0820 or 802-342-0502

 

[Bad Wolf]

Heres a used TARM down in CT. I see you're up in MA. I ahve the TARM Excel 2000 and its a very nice unit, just pricey. This one looks to be 1/2 of a new unit.

http://newlondon.craigslist.org/for/2597858550.html

Uses a single flue and has auto backup features.

 

[daveswoodhauler]

Thanks for the responses and additional info.....I really thought this thread would get poo poo'd, but you guys are great.
I've looked at some of the used units, but not knowing too much about them I have been leary of buying one used and not being the most handy/fix it type person.
My current oil boiler is 10 years old, and seems to be fairly efficient....I'm thinking I am going to take a good look at the combo units should this boiler even need extensive repair.
I saw a used TARM (wood/oil) in CT for like $900....was very surprised at the prices of new ones, ouchie!
I guess I am trying to determine how much wood I would go through in a wood/oil combo unit.....right now I used about 500 gallons of oil for DHW and heat, and used about 1 1/2 cords/year on the insert.

 

[cricco]

I have a Newmac BC 160 oil/wood boiler. I also have indirect hot water. I heat with wood, but use oil for hot water in the summer. I plan to install an electric hot water heater soon for use in warm weather. The Newmac is well insulated, and doesn't really throw off enough heat to keep my basement "heated"...but it stays fairly warm down there.

 

[Gasifier]

daveswoodhauler,

Have you made any progress/decisions on your system yet? Just curious. Was cruising through some threads and stumbled on this one from a while ago.

 

[daveswoodhauler]

daveswoodhauler,

Have you made any progress/decisions on your system yet? Just curious. Was cruising through some threads and stumbled on this one from a while ago.

Nothing really new to report here. Basically, I was looking at options down the road when our current boiler need to be replaced...looked into the cost, and right now it probably doesn't make sense. Right now I burn about 600 gallons of oil/year, and go through perhaps 1 1-2 cords with the wood insert. I'm thinking that when our current boiler may need to be replaced, we might only be in the house another 5-7 years after that as our boys will be gown up and we will be looking to downsize our home as we won't need 4 bedrooms anymore. I still read a lot of the posts in the boiler room just to learn how they operate/maintenance, etc..