Wood stove questions

[joespruce]

Hello,
I realize these questions are a bit off subject for this forum but hopefully no one minds.

I am going to be purchasing a wood stove soon and would love some recommendations regarding brands, cat. vs non-cat., etc.

I have an oil furnce currently with an unlined masonry chimney.  Is there a compatability issue if I run the wood stove off the same chimney but add a flu liner?  I don't intend to use the furnace except on rare ocassions (maybe five days total this winter) and never simultaneously with the wood stove.

Last I am wondering how feasible the wood stove installation would be as a diy project.  If anyone knows of reputable sources of info on installation I would be grateful.

Thanks for all of your input and advice,
JoeSpruce

[beenthere]

I installed the wood burners I've used..first one an Ashley warm air space heater. Second one a water jacket unit.
Neither did I try to plumb into the oil burner flue. Heard that was not allowed by code. Not sure where you are, so don't know if that is a problem for you (or your insurance co.).

Google and learn a lot about diy wood burner projects. Good luck.

I also have a Vermont Castings Defiant with cat, and like it a lot. Have to keep the cat clean of fly ash, and limit what is burned.

[simonmeridew]

Hi Joe
One of your compatability issues would be with your insurance agent. Most are not inclined to insure if you run a solid fuel appliance(wood, coal or pellets) into a flue that also vents a gas or oil burner. To do so is contrary to most modern codes. They are not impressed even if you seldom use the solid fuel appliance.
Sorry to be a wet blanket.
simonmeridew

[Gary_C]

Joe, I would not recommend using an unlined masonry chimney for any heating unit. For your family's safety put a liner in that chimney!!!

At minimum get CO detectors for all sleeping areas and near the chimney.

Most insurance companies require a class A triple wall chimney for wood burners and some will raise your premium regardless.

[RSteiner]

I second the caution not to run the woodstove in an unlined chimney, or with the oil burner in the same flue.  There are stainless steel liners that are available to line chimneys which you can do yourself. 

You may want to consider installing a metal insulated chimney specifically for the woodstove.  I have done that also and I do like that chimney better than the masonary ones I have had.

As far as woodstoves go I have had used both cat and non-cat types.  The Jotul I purchased last year is a non-cat and I like it better than the Consolidated Dutch West stove we ran for 18 years that had a cat.  I think the most important factor is the dryness of your firewood, the drier the wood the more heat you will get with a minimum of cresote.

Randy

[Ironwood]

Ditto on the liner, I spent as much for my liner as I did my Vermont Definiant. I bought the heaviest and best flexible I could find ANd it had to be 2 stories long. The piece of mind is worth every penny. We have only one flue (unlined) and direct vented our high effieciency boiler to "steal" the flue. I would NEVER reccommend combining them, as it would likely void your homeowner's AND potentially send us running out of the house some day. I cannot stress enough the piece of mind the liner provides. Enjoy yer' wood heat.


 Ironwood

[Woodhog]

I would go and have a talk with your Insurance Company before you do anything.

Here they will come in and cancel your policy if you have a wood stove that does not meet all their criteria, including the stove itself (has to have a tag on it with Underwriters Approval), it has to be properly installed, hearth, 18 inches from combustible material, and the flue has to be lined, 3 feet above roof peak etc etc etc.....

Many people have had to throw perfectly good stoves in the dump as they have no official tags on them when the Inspector comes to check your house out for Insuring, even if the install itself was done properly.

You could easily end up with your new stove installed, chiminey up and find you cant get any Insurance.

[beenthere]

Woodhog
What country do you live in?

Curious...I've never had an insurance company Inspector come and check out my house for Insuring. 

I've heard of some who have policies that say up front the home with a wood burner will either not be covered or will require additional coverage.

As well, I've encountered a local building inspector who wanted to know if the code was followed when I put the Defiant in a new addition (good information is on-line at the Vermont Castings site in the downloadable manuals).

[sawmilllawyer]

By all means follow code in your area. i installed my Earth Stove fireplace insert with a six inch stainless steel liner inside my fireplace chimmey with the liner running from the top of the stove up to four feet above the roof and weather capped. It is up to code and has reduced my gas bill significantly over the years. Be sure and inspect and clean (sweep) the flue liner periodically to prevent creosote buildup. CO2 detector is a good ideal as they are not very expensive and sure do give you a degree of comfort. I rebuilt and installed the insert myself and have been very pleased with it's performance. Like Ironwood said the SS flue liner cost almost as much as the stove but IMHO worth it. Andy.   

[joespruce]

Thanks for all the input.  I still don't understand why it is not ok to run the woodstove on the same chimney as the furnace if the furnace will not be used regularly.  Could someone please clarify this point for me?  Insurance and code issues aside, is there something inherantly unsafe about that setup?

Thanks,
Joe

[beenthere]

The fumes can backdraft (downdraft) into the unused furnace...especially if the unused furnace is cold. At least that is how I understand it.

If temps are right, I get some downdraft from my unused fireplace chimney.  Can smell the creosote in the house as the damper does not seal tight enough.

[rebocardo]

Your unlined chimney will see maybe about 200-300 degrees exhaust from the oil burner, from a wood burning stove it can be 800-1600 degrees, 2100 degrees in a worse case scenario.

Most codes will not allow any two devices to use the same exhaust flue any more. Never mind a wood burning stove

A wood burning chimney will be lined with brick/tile and grout/cement meant to be subject to the higher temperature a wood burning fire will produce. Plus, they have draft flues built in, clean out at the bottom etc. You can run triple wall pipe up that no sweat.

> Last I am wondering how feasible the wood stove installation would be as a diy project.

Entirely doable, I did mine with advice from here and other websites. I did mine according to NASD (?) specs and over built.

My floor is a plywood base, over that I did metal, cement board, tile, and under the stove a brick platform on top of the tile, and on top of the brick, a metal tray the stove sits on.  I used all triple wall stainless steel and last year I cleaned my chimney (I disassembled it to check it) with a sock.

[RSteiner]

Thanks for all the input.  I still don't understand why it is not ok to run the woodstove on the same chimney as the furnace if the furnace will not be used regularly.  Could someone please clarify this point for me?  Insurance and code issues aside, is there something inherantly unsafe about that setup?

Thanks,
Joe

One of the most significant reasons for not using an unlined chimney that also exhausts an oil burner is the condensation of cresote and the potential of a chimney fire.  The newer woodstoves are cleaner burning than the stoves from years ago but all woodstoves send unburnt volitales up the chimney which tend to condense on the cooler chimney surfaces leaving a deposit known as cresote.  Cresote is not very friendly to cement and will slowly eat away at it and cement is not the best material in high heat situations.

Chimney liners in a masonary chimney are made from a material that will withstand much higher heat and the attack of cresote.  All chimneys collect cresote or condense the unburnt volitales that leave in the smoke out of the stove.  The warmer the chimney stays the less chance the cresote has to condense before exiting the chimney.  This is where metal insulated chimneys have an advantage they warm up quicker than a masonary chimney. 

The inside of any chimney that has wood smoke pass through it has a coating of cresote and  depending on the way one burns wood, the type of wood burning device, and the condition of the wood factors into how quickly cresote deposits build up.  Periodic chimney cleaning is necessary to remove this huild up because cresote is very flammable.  Every once in a while and more often than people realize some of this cresote on the inside of the chimney burns off, if there is a large quanity that gets to burning the whole chimney can become a torch.

Now picture an unlined chimney that can not withstand a great deal of heat that has a build up of cresote on a chimney that is shared with an oil burner.  The woodstove is burning and the cresote gets to burning the oil burner kicks in and supplies the burning chimney with a forced draft and you have just turned up the heat on an already hot situation.  Plus most oil burners need to have a damper which allows the chimney to take in air at some point which I think is to allow the chimney to purge itself of flammable fumes from the oil burner so there will not be an explosion in the chimney the next time the furnace starts.  I don't think this damper would allow the chimney to draw properly with a woodstove connected to it.

Wood has been are primary source of heat for 34 years, we have no other source of heat, there have been a couple of insurance companies that will not even consider giving us coverage because of this.

Randy

[John Mc]

A good web site for wood burning questions in general, with some stuff about wood stove installations, IIRC:  http://www.woodheat.org

John Mc

[Woodhog]

Woodhog
What country do you live in?

Curious...I've never had an insurance company Inspector come and check out my house for Insuring.  Roll Eyes Roll Eyes Roll Eyes

Just up here in Canada... Our Insurance company has  full time inspectors, they will show up on your door step anytime and ask to come in an look around, they check everything electrical, plumbing, roof, and are really sharp on wood burning devices...

They fill out a checklist type form and you have so many days to comply with any defects or your coverage is cancelled.

I sort of like it because it makes a good free safety inspection, this company gives back a refund almost every year to the customers if their claims are below a certain amount.

However the initial reaction is to throw him out as it usually costs money to comply with the check list items...

[den]

Here is the best place to go pertaining to wood stoves.
http://www.hearth.com/
http://www.hearth.com/econtent/index.php/forums

Here for coal.
http://nepacrossroads.com/

[thecfarm]

I had an insurance guy come here to check out my place. He did not need to come inside.We wasn't home anyways.Don't really see how a home can really be checked that way.They wanted to know if my boiler was installed by a lincesed company.Had to tell them yes,but it's a outdoor furnace,not inside the house. 

[RSteiner]

New Hampshire just passed new regulations concerning outdoor boilers.  The new regulations even apply to exsisting installations.  The boilers can not be closer than 200 feet from neighboring houses, the smoke stack has to be 3 feet above the roof of any building within 300 feet.  That will limit the places boilers can be installed. 

I believe on any new installation the boiler has to pass EPA emission requirements also.  I guess too many outdoor boilers left the neighborhood in a cloud of smoke.

Randy

[thecfarm]

You sound like my FIL.I told him I was going to get one and all he could say was,they smoke,they smoke.Mine does a very good job on the smoke dept.I used it all summer long.I like to tell him it's going when he comes up.Just depends on what you burn for wood and how dry it is.I burn ALOT of junk wood in mine.The smoke will pour out of it with junk wood..When I burn green wood,same way,but I think alot of that is steam.I am burning good,dry hardwood now just for hot water and to keep the hot tub warm.Does not smoke all that much.I've seen my cook stove smoke more at times.

[SwampDonkey]

Woodhog
What country do you live in?

I don't know what that means. But, if your the insurer, I think it's your right to know the risk.

They come looking here to, beenthere. When everyone was told to replace oil barrels the agents came in and took photos and you had to have a certified installer do the work. My agent came here 3 times, once to tell me the oil barrel had to go, a second time to look at the job and a third time to take photos. He also didn't like the idea the oil furnace and wood furnace vented into the same flu. I said where else would it go? The issue was dropped.

My uncle refused to replace his oil barrel and his insurance was canceled. Some lose insurance because of the flu, especially old flues with no liners. If you tell them it ain't lined, kiss the insurance good bye.

[Gary_C]

 Some lose insurance because of the flu, ........... If you tell them it ain't lined, kiss the insurance good bye.

You lose your insurance if you are sick?   

And then you have to kiss them?             

[SwampDonkey]

 

[Sprucegum]

Only in Canada, eh?   

I have a zero-clearance fireplace with an insulated(Selkirk) chimney all the way. No problem with insurance, he wouldn't even come and look when I invited him 

I also have a natural gas furnace with its own chimney that kicks in whenever I'm not home to tend the fire.

[Radar67]

Anybody got a Hardy outdoor wood furnace? Heard anything bad on them?

[SwampDonkey]

Only in Canada, eh?   

I have a zero-clearance fireplace with an insulated(Selkirk) chimney all the way. No problem with insurance, he wouldn't even come and look when I invited him 

I also have a natural gas furnace with its own chimney that kicks in whenever I'm not home to tend the fire.

For one thing they are not experts, they just look for things the insurance company ask them to. An old oil tank, two heating appliances vented to the same chimney that sort of stuff doesn't take an expert to confirm.

[deutz4]

When I put up my new house, my insurance agent had to come out and take pictures to make sure I was playing by their rules and the stove manufacturer's recomendations. He even moved the pail of kindling which I had setting too close to the stove for their rules. I do pay a $100 "bonus" for having a woodstove but my savings on gas make it a piddly fee.

[Lurcherman]

I'm trying to put in a coal stove. I called my insurance company to ask how it would affect my rates. They asked to clarify - coal or wood stove? I said coal, and I was told coal "doesn't count" and won't affect my rates at all, but wood does. A wood stove would bump my rates up by a not-insubstantial amount. The reason being that coal burns clean, and with zero risk of a chimney fire.

[SwampDonkey]

Not too long ago, somebody testified in here that his rates dropped because he installed a wood appliance. As I always said, there is no equality in the insurance business.

[ohsoloco]

My insurance company didn't seem concerned that I am heating my house with a woodstove.  They just wanted to know that it wasn't a homemade stove.  They also wanted a picture of where the stove pipe goes through the wall to connect to the flue.  Just snapped a few pics and emailed them.   

I'm just glad I'm heating with wood.  It would be DanG cold in my house this winter if I were heating with oil 

[LorenB]

I am going to be purchasing a wood stove soon and would love some recommendations regarding brands, cat. vs non-cat., etc.

JoeSpruce

Joe,

The current issue (November 2008) of Fine Homebuilding magazine has a brief, but surprisingly thorough, article on many different types of wood stoves.  I recommend the article. 

One conclusion I made after reading it, and after talking to a chimney sweep friend, is that there is no longer any reason to buy a catalytic stove.  The modern non-catalytic stoves meet all the emission requirements. 

I have a Temp-Cast.  It's a masonry stove/fireplace that is basically a kit.  It's an excellent unit.  In fact, excellent is not enough to describe it.  Send me a PM if you want more detailed information.  Or you can go here:
http://www.tempcast.com/

Loren

[LorenB]

...Plus most oil burners need to have a damper which allows the chimney to take in air at some point which I think is to allow the chimney to purge itself of flammable fumes from the oil burner so there will not be an explosion in the chimney the next time the furnace starts.  I don't think this damper would allow the chimney to draw properly with a woodstove connected to it....

Randy

Randy,

Good explanation of creosote and why not to have two appliances venting into the same flue.  Thanks. 

The damper you mentioned is not to allow purging of the chimney.  It's to prevent the chimney draft from getting too high.  If a chimney is particularly long or gets good and hot, it will draw more air up itself than the appliance is capable of supporting.  Too much draft will "lean out" the fuel-air mixture on the appliance. 

If you install a barometric damper, it will open when the chimney draws too much air and the damper will supply the extra air instead of having it sucked from the appliance.  If the chimney isn't drawing properly in the first place, then the damper will remain closed and all of the chimney's suction will pass through the appliance.  My wood-fired, indoor boiler uses a barometric damper. 

I hope that's clear.  If not, let me know and I'll try to write a better explanation. 

Loren