Combination wood/oil furnace replacement

[weedsportpete]

Does anyone have experience with combination wood/oil furnaces? Are they worth keeping? [img]/forums/images/icons/confused.gif[/img]

We moved in recently and were told by previous owners that the wood part was the backup to the oil part. We just had it inspected and serviced and were told that the oil is the backup for the wood.. [img]/forums/images/icons/tongue.gif[/img]

And that being 12 years old, depending on how much wood was burned, it was past its life-expectancy.. [img]/forums/images/icons/tongue.gif[/img] And that the oil part was about 50% as efficient as an oil-only furnace. [img]/forums/images/icons/tongue.gif[/img]

Two previous owners, and the serviceman, told us that this furnace is expensive, but now I'm wondering if it is worth keeping..

Certainly I don't want to spend the money on a new one (and he says that the duct work will be expensive, but I wonder about that..). If its true that the wood side is more efficient, then I can understand that, but we're not ready to start going into the basement once or twice a day to add wood to the fire. That will end up being my chore anyway.. [img]/forums/images/icons/grin.gif[/img]

PS the make of the furnace is NewMac, out of Canada.

Here's my questions:
- is the oil really a backup for the wood?
- if the previous owners used wood 80% of the time, does that mean that this 12 year old furnace is due for replacement? [img]/forums/images/icons/frown.gif[/img]
- is it really 50% as efficient as a oil-only furnace?
- just because a LP gas furnace is 95% efficient, does that make more sense to buy than a new oil furnace (if I buy something)?
- will there be soot on the walls?? [img]/forums/images/icons/confused.gif[/img]
- does anyone have any experience they can share?

Pete

[pbenven]

Those are highly coveted heating units in these parts. A new one will likely run about 8 - 10k CDN.

To answer your question with a question, how could wood possibly be a back-up to oil? When the oil runs out a fire is automatically started? No. In this sense, the oil is a backup to the wood. You start a fire in the morning and then go about your business. If the fire goes out or you're occupied for longer than you think, the temperature will drop and the oil furnace will kick in.

You could look at it from a different perspective, I suppose. You use oil primarily and all of a sudden you run out. It's Sunday night, and there's a blizzard outside so no delivery is possible. You start a wood fire. In this case I guess the wood would be your backup.

Either way, having two heat sources is better than one.

Sorry I can't answer your question about life expectancy of these units, although 12 years does not seem long to me.

It may be a bit of a pain to keep the thing burning, but the heat you get is worth it - it's the very definition of the word warm.

[dlabrie]

I have a FHW oil system with a Wood furnace attached. Once it gets below freezing on a regular basis, the wood furnace is fired up and is rarely out. If it does go out, the oil kicks in. The combination is about 30 yrs old. Because of the age of the system, it is not all that efficient but keeps the house nice and warm. I cut my wood for free so I don't mind. The only problem I have is if the power should go out. Then the circulators can't run and the boiler could blow off into the fire box, extinguishing the fire (for safety reasons) and making quite a mess. That has only happend once. Sinc then, if the power goes out, I make sure the fire is knocked down and the vents are clossed.

I would really like to retire the old wood furnace and buy a new one that goes outside and is connected to the oil system via underground insulated tubing. Then all the mess would be outside and the wood pile close by. Not to mention much more efficient. Just don't have the $$$ to do it now [img]/forums/images/icons/frown.gif[/img] .

David

[GaryM]

It wouldn't take a very big generator to run the circulator pump. Then the boiler wouldn't blow off, and the house would be warm too. Of course if you're not home...

[dlabrie]

Gary, you are right. I have thought about that and the sad part is... I already have the generator [img]/forums/images/icons/blush.gif[/img] . I just need to take the time to make a connection on the 'dump' circulator so that it cuts it off from the power grid. It's one of those things you plan to do when the power goes out, but....
David

OK, I'll get back to work [img]/forums/images/icons/smirk.gif[/img]

[weedsportpete]

Thanks Paul,

maybe I should think more positively about staying with wood.. just something new to get used to, like everything else out here in the country. [img]/forums/images/icons/smirk.gif[/img]

Pete

[EJB]

If you just moved into the place, best to give the unit a few years worksout before rushing into anything...I for one wouldlove to have a setup like yours...a oil/wood combo.

I have more wood on my property than ten people could burn in their lifetimes so I'd love to be able to use more of it and keep my oil dependency down...then again, its hard to justify spending that kind of money to replace a perfectly good oil FHW system that I already have.

You never know...you may actually enjoy processing all that wood some day [img]/forums/images/icons/smile.gif[/img]

[RichS]

When we purchased our current place it had two units (one oil, one wood) both connected into the FHW system. We have been running on it for two winters now and it has been very good. I concur with the other posts here that it is a big peace of mind to have two sources of heat. We burn wood almost exclusively during the winter months and the oil savings are quite welcome.

It did take a little getting used to as both units are 20+ years old and no paperwork on either. But with some help from the local furnace cleaner/inspector I have figured how they interact with each other.

The only way there would be soot on the walls if you don't open the dampers prior to putting wood in and smoke comes out through the opening. If you open the dampers properly prior to loading it up with wood, then you shouldn't have any problem. Also if it has a big capacity for wood bring your wood to the furnace prior to opening. Then you can open it up only once and put all of the wood in. I have seen times, that with all of the coals if you open and close it multiple times to put the wood in that the first wood you put in ignites and you do get some smoke out the opening.

Also remember that as with any wood furnace it is imperative that you keep the chimney cleaned at least yearly. If you burn good dry wood then less creosote is generated but even so some will be and chimney cleaning is required.

Just my experience. Hope it helps. [img]/forums/images/icons/smile.gif[/img]

-Rich

[weedsportpete]

Thanks guys.. that does help.. I should give it a try before dismissing it out of hand.. I need to clean up around there anyway.

[Mike_Dumond]

Pete, as a former heating contractor, let me say that you have a good combination furnace. Have it serviced by someone who knows the newmac brand, and ask alot of questions. You'll like it.

Now, with that said, let me add this to anyone looking to purchase a combo unit. Don't. You can get a really good oil unit, and you can get a really good wood unit. But, when you put them in the same unit, you have to give up a little from both to make it work. Side by side is the way to go. A little more expensive to start, but you'll more than make up for it in the longrun with the savings from increased efficiency.