ONE chimney for 2 Boilers?????

Code does not allow .... but common sense does.

Maine allowed 2 appliances on one flue in the late 1980's as this is what I did with a oil boiler and a coal and wood boiler all professionally installed . I have been burning wood with oil back up for all these years with no problems at all and at times both running at the same time but not very often. I do make sure my chimney is kept very clean. I have a baro damper on the oil boiler only .My insurance company is well aware of the install as they just checked this past year and I am grandfathered in I guess. The only thing they wanted to know if the wood @ coal boiler was UL approved .I would like to change over to coal this next season just don't know if I will have any problems with this same type hook up, I have a New Yorker coal @ wood boiler. I am sure local codes could have been different in many areas of Maine during that time period.

hcarlow wrote:Maine allowed 2 appliances on one flue in the late 1980's as this is what I did with a oil boiler and a coal and wood boiler all professionally installed . I have been burning wood with oil back up for all these years with no problems at all and at times both running at the same time but not very often. I do make sure my chimney is kept very clean. I have a baro damper on the oil boiler only .My insurance company is well aware of the install as they just checked this past year and I am grandfathered in I guess. The only thing they wanted to know if the wood @ coal boiler was UL approved .I would like to change over to coal this next season just don't know if I will have any problems with this same type hook up, I have a New Yorker coal @ wood boiler. I am sure local codes could have been different in many areas of Maine during that time period.

You are "grandfathered".......but if you replace the the current wood boiler with a coal boiler.....all bets are off! You are no longer grandfathered. A friend of mine is going through this process as we speak. He has a brand new AHS coalgun ready to replace the wood boiler, but the insurance company and state of Maine say "no" to the double flue in the chimney hookup. He can do it according to the state of Maine as long as he removes the electricity and the oil gun off the oil boiler......and then remove his oil fill pipe outside the house! WTF!!! That way both appliances can't run at the same time. He has a manual switch for his oil boiler.....there's no way it can fire. He's been doing it for years with no problems. This guys nows what he's doing. Also, there's no way he can powervent the oil boiler because of it's location. He doesn't know what to do. I'm sure he'll figure it out....he's a smart guy.

sterling40man wrote:

hcarlow wrote:Maine allowed 2 appliances on one flue in the late 1980's as this is what I did with a oil boiler and a coal and wood boiler all professionally installed . I have been burning wood with oil back up for all these years with no problems at all and at times both running at the same time but not very often. I do make sure my chimney is kept very clean. I have a baro damper on the oil boiler only .My insurance company is well aware of the install as they just checked this past year and I am grandfathered in I guess. The only thing they wanted to know if the wood @ coal boiler was UL approved .I would like to change over to coal this next season just don't know if I will have any problems with this same type hook up, I have a New Yorker coal @ wood boiler. I am sure local codes could have been different in many areas of Maine during that time period.

You are "grandfathered".......but if you replace the the current wood boiler with a coal boiler.....all bets are off! You are no longer grandfathered. A friend of mine is going through this process as we speak. He has a brand new AHS coalgun ready to replace the wood boiler, but the insurance company and state of Maine say "no" to the double flue in the chimney hookup. He can do it according to the state of Maine as long as he removes the electricity and the oil gun off the oil boiler......and then remove his oil fill pipe outside the house! WTF!!! That way both appliances can't run at the same time. He has a manual switch for his oil boiler.....there's no way it can fire. He's been doing it for years with no problems. This guys nows what he's doing. Also, there's no way he can powervent the oil boiler because of it's location. He doesn't know what to do. I'm sure he'll figure it out....he's a smart guy.

well.... he could run both of them together and keep his mouth shut like the rest of the country.

Yes you are right, but forunately for me my boiler is both for wood and coal . If you make a change and keep your mouth shut as suggested and have a claim caused by either appliance the insurance company doesn't have to make good on your claim. I would like to change to a more efficient coal appliance but not sure it will even be possible as they know the make and model of my present unit. My local insurance agent implied to me that insurace company's want nothing to do with coal or wood if they can help it.I can kind of understand the wood thing but not coal.I don't really want to go with the forced air vent system . Look at all the pellet stoves being installed ,are they any safer than a coal stove? What are people supposed to do with the cost of oil going so high? I will try burning coal in my wood and coal boiler I have for a year and see how I make out. The boiler is 23 years old and doesn't have any real good baffle system so I am sure I will have a good amount of heat loss. The effiency when burning wood didn't really matter much as wood use to be so cheap , not the case anymore.

get a different insurance company, most don't ask and don't care as long as you have a primary (oil, gas, electric etc.) heat source and don't have a wood stove.

Berlin wrote:get a different insurance company, most don't ask and don't care as long as you have a primary (oil, gas, electric etc.) heat source and don't have a wood stove.

That's exactly what I will have to do I guess ,after I burn up the wood that is left over, or just tell the one I have I took out the wood boiler and not say anything about a coal stove.

hcarlow wrote:

Berlin wrote:get a different insurance company, most don't ask and don't care as long as you have a primary (oil, gas, electric etc.) heat source and don't have a wood stove.

That's exactly what I will have to do I guess ,after I burn up the wood that is left over, or just tell the one I have I took out the wood boiler and not say anything about a coal stove.

There's no real safety risk with installing two appliance in the same flue - as long as one of them doesn't burn wood; even then, properly operated the risk is low. If you install the new appliance safely with proper clearances etc. it won't cause a loss and therefor whether your insurance company knows about it or not isn't an issue. But, as i've said, you could always go with an insurance company that doesn't ask and doesn't care (most don't as long as your not talking about woodstoves, sometimes fireplaces) and you'll have even more peace of mind.

See here http://www.hearth.com/talk/threads/wood ... ast.41161/ (read quite a way down)

And here New guy with venting questions.

Regulations in Maine changed around 2008, basically to allow for more flue-sharing, but I don't know the exact details.

Did I actually hear 'common sense' mentioned....Smitty, damned you...you know the 'POINTY HEADS' WILL ABSOLUTELY FREAK OUT AT THE MERE MENTION OF SOMEONE USING 'COMMON SENSE'. I think the black Tahoe Guys will be knocking on your door in the EARLY AM. I sure hope they enjoyed the 'Female Company in Columbia', however it seems that some sort of monetary compensation was not successfully negotiated AFTER the 'test drive' as they called it. It's always about money isn't it???

Code was and is designed around wood fired appliances, and creosote issues......but $%ASDXCOFUIG)_(*YHOIHYTG(_*Y}(_(H}GOHOHGFO&IUTGPU paragraph and subset says: 'No can do'.

Liability is a damned serious issue, especially if you are the one liable! .....and in my mind, I sure want to have no part in causing something to harm, injure or worse to any fellow Americans. One wonders if the type of clothing you wear might be an issue also. Headgear for example could fall partially into a fire....oh well, that is another issue. Night, fellow black rock burning non-pointy headed individuals.

Ah, more great heated discussion....

Common Sense - the more you know, the more you realize what you don't know. Those that know little think they know everything and that if the code allows it, it is then OK. So, the code must become more strict to protect people from those who think they know everything.

Two appliances into one flue creates more variables to deal with. Every commercial building that I have every been in that had old solid fuel appliances into a common chimney had a complex draft control system to deal with the variables.

I would avoid running two appliances into one flue regardless of code, especially if they are two different fuels. I would even avoid running two different types of appliances firing the same fuel into one flue because they may prefer different draft settings. Also, big flues do not make for better draft if they are oversized. One appliance into a flue designed for two during mild weather could have problems.

yea, there are those that done combined flues sucessfully. There are also those that haven't. Why take added risk to save a few dollars?

Apply the KISS method. One appliance into one flue.

According to the state fire marshalls office , Maine has about 500 chimney fires per year,they also stated " not one fire in the past several years had anything to do with two appliances on one flu " . I could be wrong but it looks like from what I read homes built before 1998 can do upgrades with the two appliances on one chimney even with wood.There was legislation to allow all homes but I haven't been able to find out the outcome of that legislation yet . I think insurance companies are not being thuthful with people for their own reasons or have no idea what the laws really are.

hcarlow wrote:I think insurance companies are not being truthful with people for their own reasons or have no idea what the laws really are.

Dishonest insurance companies?!? I am shocked!