Chimney Liner dilema?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

lavs4x4

New Member
Sep 1, 2009
21
Central Maine
Hey guys just got my Essex wood boiler fired up for the first time since we moved in the new house works great!. The unit was used as a backup for the oil fired Pensotti furnace. I plan to have the Essex as my primary heat source. So, in preparation I had 2 chimney sweeps come over and inspect the 22ft chimney, as expected the chimney is not up to the task. This is and early 1800s farmhouse. The terra cotta liner is cracked in a number of places and the second tile from the top is off kilter. One sweep wants to knock out all the tile and install a 7in stainless liner re grout the chimney and install a cleanout in the basement for $1750. The other sweep wants to repair the terra cotta by taking the brick down to below the roof line and repair the cracks and rebuild, for $1250. Both options are pricey for me right know but I want to get this thing running fulltime and sleep comfortable knowing the job was done right.

After many hours reading past threads and reasearching liners my third option would be to undertake this job myself. I talked with the guys at Magna Flex and he was thinking I could use a 5.5in uninsulated liner throught the current clay flue ( interior dia 6"x6"). My concern is a 5.5 may not be large enough for both my wood boiler and oil fired backup unit.

Just wondering what my best bet is? Trying to do the job right and spend the least amount of money. I wouldn't be opposed to knocking out the terra cotta myself but looks like a major pain.

Any help would be great. Starting to get cold up here..

Thanks,
Frank
 
Nothing ever said about 2 flues in 1 chimney? Its a no no. Each appliance must have its own flue.
 
Yes that has been discussed. I have also done alot of research on this topic and feel confortable with the right liner this setup will be fine. A professor at the Umaine has done extensive research on this and hasn't been able to proven it is a problem. The oil furnace will strictly be for backup purposes aswell.
 
Well its against code. If there was a house fire, the insurance wouldn't cover the damage. If you were burning wood, and the chimney did plug and the oil heat would kick in, the flue gases would backup into the house. Just some thoughts.
 
I agree, don't use the same chimney for both. but can you power vent the oil furnace. That way you can be to code and safe and also not have a problem with size.
leaddog
 
I thought both units could vent to the same flue when only one would be used at a time.
 
What's the rated output of the Essex? A 5.5" flue with wood is going to be worth maybe 65-70,000 btu's. Anything past that and you are not going to have enough draft to vent properly.

Personally, I don't recommend the use of flexible SS liners for wood. The corrugations in the tube are excellent spots for creosote to begin accumulating. Rigid sections riveted together is the only way I will do a liner for wood.

I"m afraid I don't see a good (inexpensive) solution to your problem.

BTW, both of the options offered by the sweeps are far far less expensive than the alternative. (chimney burnout, CO in the house etc.)

Do it right, and you'll only have to do it once.
 
There exists a "tool" which is a plate of steel of square configuration, smaller than the inside of the terra cotta tile. It fits on the end of a drill... :) You insert this into the opening and turn it on, it breaks the tile into little pieces which your shovel out the cleanout at the bottom... ayuh. Can be done, has been done, doesn't make it easy.

Unsure why one would spend 1800 dollars to tear down brick, and repair junk that will have to be repaired some more after one decent chimney fire, or outright replaced. Seems to me, 1,800 bucks would be better spent:

1. Bust out the old tile.
2. Install a nice insulated stainless liner that would withstand a decent chimney fire or two. They're made and not awful to install.

The two appliances into one flu? Depends on local codes, set-up initially existing, and insurance company.

State Farm said, "We don't care, but it has to be set up so they can not both operate at once. When one is shut off, the opening into the flu has to be mechanically blocked."

What it sounded to me like was alot of expensive and automatic mechanisms to go wrong... power venting the oil burner would be the best option... then you're set to dedicate the chimney to the wood burner. Safest and soundest, allowing you to sleep at night.

Other option is hook one up at a time, not real practical... and far from "automatic"...

lavs4x4 said:
Hey guys just got my Essex wood boiler fired up for the first time since we moved in the new house works great!. The unit was used as a backup for the oil fired Pensotti furnace. I plan to have the Essex as my primary heat source. So, in preparation I had 2 chimney sweeps come over and inspect the 22ft chimney, as expected the chimney is not up to the task. This is and early 1800s farmhouse. The terra cotta liner is cracked in a number of places and the second tile from the top is off kilter. One sweep wants to knock out all the tile and install a 7in stainless liner re grout the chimney and install a cleanout in the basement for $1750. The other sweep wants to repair the terra cotta by taking the brick down to below the roof line and repair the cracks and rebuild, for $1250. Both options are pricey for me right know but I want to get this thing running fulltime and sleep comfortable knowing the job was done right.

After many hours reading past threads and reasearching liners my third option would be to undertake this job myself. I talked with the guys at Magna Flex and he was thinking I could use a 5.5in uninsulated liner throught the current clay flue ( interior dia 6"x6"). My concern is a 5.5 may not be large enough for both my wood boiler and oil fired backup unit.

Just wondering what my best bet is? Trying to do the job right and spend the least amount of money. I wouldn't be opposed to knocking out the terra cotta myself but looks like a major pain.

Any help would be great. Starting to get cold up here..

Thanks,
Frank
 
I believe the output of the Essex is in the 175,000+ BTU output. The owners manual states a 6 in flue is recommended. I was afraid the 5.5in liner wouldn't suffice for the Essex so you guys just confirmed this. I not real familair with power venting the oil furnace. I assume it gets directly vented out the side of the house, is this correct? What is needed to be up to code in this application. I do want this setup to be as safe as possible, and yes money is tight but, I don't want to cut corners.

Thanks for the help and keep the advice coming.

Frank
 
lavs4x4 said:
I believe the output of the Essex is in the 175,000+ BTU output. The owners manual states a 6 in flue is recommended. I was afraid the 5.5in liner wouldn't suffice for the Essex so you guys just confirmed this. I not real familair with power venting the oil furnace. I assume it gets directly vented out the side of the house, is this correct? What is needed to be up to code in this application. I do want this setup to be as safe as possible, and yes money is tight but, I don't want to cut corners.

Thanks for the help and keep the advice coming.

Frank

Powerventing the oil burner essentially involves talking to your oil heat guy, as it depends on the burner, boiler, etc.. as to just what it takes to do.

If the Essex is reccomending a 6" flue, you MIGHT be able to get away with a 5.5", especially if it's an inside chimney w/ really good draft, and you can connect to it with a minimum of bends and so forth... Again, it comes back to the question of what your inspector is willing to buy off on. Note also that there is a certain amount of debate about whether a bare liner is sufficient to repair a defective chimney - at least some readings of the NFPA says it isn't....

What certainly should be acceptable would be to bust out the existing tiles and just use the brickwork as a "chase" to enclose an HT103 grade "Class A" prefab chimney. Still another option, and I don't know how it works pricewise or if you can get it done in your neighborhood is to get one of the poured in place cement relining jobs done - I've heard mixed reviews on them in some cases, but your situation sounds like one that might work for something like that.

Gooserider
 
Status
Not open for further replies.