Sweeper doesn't recommend insulated liner !?

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David_QC

David_QC

New Member
Jan 13, 2015
59
Quebec
I have a Max Caddy furnace, my chimney is unlined 40ft long and diameter is approx. 8 inch round.
Chimney is exterior maconery built with stone.
I'm living in Quebec, cold weather.

The draft without liner and the barometric control closed = .11 (manufacturer recommend 0.06 max)

I asked to sweeper a quote for insulated liner, he told me that it is not required as the maconey chimney and air around the liner is sufficient for insulation. He told me that the insulation will get wet and full of moisture and will affect liner's life span... he never install insulated liners... he seems to have lot of experience...

I am more concerned about performance than creosote, as my new furnace will probably burn much more particules than my old air tight woodstove and I plan to sweep every year.

Other fact, he can't install a liner of 6 inch in my chimney, he will use a 5.5 inch, no problem ?
 
Just called another sweeper in town, he told me same thing, he rarely install insulated liner, just in particular cases...
 
Someone much more knowledgable than me will respond, I'm sure, but I can share my experience. I had my fireplace insert installed before I read a lot about it, so the dealer just installed the stove as per their usual. My impression from talking to them and others is that most dealers/installers have meeting code specifications as really their only priority. They are not really thinking about enhancing stove performance in addition to meeting the local fireplace/stove fire safety codes. They are happy to address performance issues for educated customers, but I don't really think they do this necessarily for every installation if they are not asked. Or maybe I just don't know any decent dealers in our area.

So my stove is installed with a basic single-wall stainless steel steel liner (m-flex) and some insulation stuffed into the damper area of the firebox. There is a rain cap on the chimney with metal flashing turned down over the edges of the pre-existing square ceramic flue liner tiles; the flashing is attached with screws. My brick/masonry chimney is on the side of the house and around 20ft in length.

Most experienced burners would say that this is not the ideal setup - and they're probably right. Had I known, I would have asked for at least an insulated liner. On the other hand, our new insert heats like mad and makes little creosote. From a cold start it lights off very easily without backpuffing and I can't imagine it running any hotter. In February during a particular cold spell I had been running the insert for week straight. I went out with an infrared surface thermometer and measured the temperature of the chimney directly behind the fireplace. It was within 1/2 degree of another external wall of our house farther away. So if I'm losing heat up the uninsulated flue liner I don't think it's a lot.

I've never thought about the insulation becoming wet over time, but it seems it's possible.

Maybe there's some truth to what your sweep is saying.

I have though that maybe in a couple years I'll change out my current liner for an insulated one - but if the stove is working so well, is it worth it??

Looking forward to other comments about this.
 
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Oh boy. Here we go.

Popcorn.gif
 
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Calling on bholler! I'm sure he will have something to say - he gives good advice.
 
NYSB said:
Someone much more knowledgable than me will respond, I'm sure, but I can share my experience. I had my fireplace insert installed before I read a lot about it, so the dealer just installed the stove as per their usual. My impression from talking to them and others is that most dealers/installers have meeting code specifications as really their only priority. They are not really thinking about enhancing stove performance in addition to meeting the local fireplace/stove fire safety codes. They are happy to address performance issues for educated customers, but I don't really think they do this necessarily for every installation if they are not asked. Or maybe I just don't know any decent dealers in our area.

So my stove is installed with a basic single-wall stainless steel steel liner (m-flex) and some insulation stuffed into the damper area of the firebox. There is a rain cap on the chimney with metal flashing turned down over the edges of the pre-existing square ceramic flue liner tiles; the flashing is attached with screws. My brick/masonry chimney is on the side of the house and around 20ft in length.

Most experienced burners would say that this is not the ideal setup - and they're probably right. Had I known, I would have asked for at least an insulated liner. On the other hand, our new insert heats like mad and makes little creosote. From a cold start it lights off very easily without backpuffing and I can't imagine it running any hotter. In February during a particular cold spell I had been running the insert for week straight. I went out with an infrared surface thermometer and measured the temperature of the chimney directly behind the fireplace. It was within 1/2 degree of another external wall of our house farther away. So if I'm losing heat up the uninsulated flue liner I don't think it's a lot.

I've never thought about the insulation becoming wet over time, but it seems it's possible.

Maybe there's some truth to what your sweep is saying.

I have though that maybe in a couple years I'll change out my current liner for an insulated one - but if the stove is working so well, is it worth it??

Looking forward to other comments about this.
Click to expand...
I wouldn't worry about it if the insert is heating the desired intended space..... Having Dryer hard wood is more important.....
 
fire_man said:
Calling on bholler! I'm sure he will have something to say - he gives good advice.
Click to expand...
I'll tag him so he will see an alert to come on over...that's called givin B a holler ;lol Yo, @bholler

I would think a 5.5" liner would be absolutely fine since you have such a tall chimney. I would really want to put insulation in if it will fit! JMO
Never heard of concerns of wet insulation...at least if the liner is installed correctly
 
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Hi guys. Well i am not positive on Canadian code but i know that here you need clearance between the outer masonry wall of the chimney and any combustible materials if you don't have that which in your case would need to be 1" it needs insulated to meet code. If you do have that i would still strongly recommend that you have it insulated You obviously don't need more draft but with an exterior chimney 30' tall in Canada you will have a really hard time maintaining enough heat in the stack to prevent creosote. Then what is the chimney and why cant he get a 6" in there? I would not recommend a 5.5 for a furnace at all unless the manufacturer saws it is ok.
 
I know SBI didn't have an issue when I installed a 5.5" liner on our Caddy. We have a 32' chimney and it produces more than enough draft for the proper operation of the furnace.
 
What kind of chimney is it that is round unlined?
 
Lake Girl said:
WETT certification may be required by insurance
Click to expand...
The installer should be WETT certified. Almost all are. I've talked to WETT installers who were obviously not to standards I would accept BUT your home insurance company will require it.
 
bholler said:
What kind of chimney is it that is round unlined?
Click to expand...

It is 8 inch round unlined, he mesured it a few time, I think it is not exactly 8 but really close to, he want to install 5.5 because 6 he would have to break apart the top of the chimney and redo some masonery, which would cost more and he think that 5.5 is just fine for the draft... I didn't ask more detail about the top of the chimney... i called PSG technical support, they told me they can't garantee it would work because they didn't test the furnace with a 5.5, but they are confident that I would have sufficient draft for good operation.
I have another sweeper coming next week, he still not recommend insulation, but at least I will see if he can install 6 inch.
 
David_QC said:
It is 8 inch round unlined
Click to expand...
Is it masonry? I'm no chimney expert, but I have never heard of a round masonry, maybe they exist, I dunno.

David_QC said:
i called PSG technical support, they told me they can't garantee it would work because they didn't test the furnace with a 5.5, but they are confident that I would have sufficient draft for good operation
Click to expand...
It will have good draft, will definatly need a damper, maybe two. I remember reading here somewhere about a guy with a similar situation, had to use a barometric damper and a manual damper to get his draft under control!

David_QC said:
I have another sweeper coming next week, he still not recommend insulation, but at least I will see if he can install 6 inch.
Click to expand...
I would sure think a 6" would fit in a 8" ID flue, unless the joints have tons of extra mortar that oozed out. Shouldn't be too hard to knock that mortar off if that is the case though. Not only a 6" should fit, but my thinking is a 6" with insulation should fit, 1/4" insulation if not 1/2".

Is that the chimney we are talking about in your avatar pic?
 
maple1 said:
Just wondering what is behind a new liner? Is there something wrong with the chimney?
Click to expand...
PSG recommends a 6" flue. You have a point though, if the chimney is OK, I'd be real tempted to try it as is, see how it works
 
maple1 said:
Just wondering what is behind a new liner? Is there something wrong with the chimney?
Click to expand...
It is unlined that is what is wrong with it. Is it the old concrete blocks with the round center? If so line it those were fine in their time but every one i have seen has deteriorated to the point you cant clean them well. And if it is 8" round just open up the top and put in a good 6" insulted liner. This is a furnace that will probably have a baro damper on and will probably make a decent amount of creosote. Do it right and be safe I would never put 5.5 because you will get a top ring of buildup which most people do if you are already right on the edge of enough volume you will be up there all the time cleaning.
 
brenndatomu said:
PSG recommends a 6" flue. You have a point though, if the chimney is OK, I'd be real tempted to try it as is, see how it works
Click to expand...

That's what I was getting at I guess. The furnace is a clean burner, and the chimney has more draft than required. So on the face of it the existing chimney should be good - so wondering if there is a structural issue?
 
Guess I was typing at the same time as bholler.

Still some uncertainty in my mind - 'unlined' might not really mean unlined but rather a clay liner, and I don't know how you could get a round chimney hole out of a masonry chimney without one, unless there maybe is concrete blocks with round holes in there too? Further clarification might help - maybe a pic looking in from the top?
 
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I have no problem so far with my chimney, both side unlined, I used it for 3 months with a temporary installation of the max caddy, I can control draft at 0,06 with barometric controller with a few washer to add more weight, it stays almost full open to keep the draft from 0,11 to 0,06.
I hope that a smaller diameter liner would get me less draft and i could remove these washer and lose less of my basement air out of the baro. Does diameter affect the same as height, any physicians here ? :- P

The only problem so far with my chimney is that I have some "effervescence" caused by my oil burning furnace on the other side, but this will be replaced by the max caddy and one side will be not used.

It was my first winter owning this house

I uploaded some pics...
Thanks for your time
 

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From those pics i cant tell what the construction of that chimney is but I can tell it is not the round center blocks. Regardless i can see cracks in what ever is there so it needs lined. Smaller diameter will increase draft to a certain point than it will start to reduce it again. The thing an insulated and properly sized liner will do is that it will stabilize the draft and make it very consistent. Another thing i see is that your furnace is positioned wrong the vent pipe is way to long and has way to many elbows in it this will add to the buildup of creosote. Which i can tell has been an issue from the creosote stain running down from the crock. What ever you do make sure you have the chimney cleaned very well before installing any liner. If these guys do not typically insulate liners i would not count on them properly cleaning the chimney first either because they are already cutting corners. I am also pretty sure i can see framing in contact with the masonry there which means that by code you need to have the liners insulated.
 
bholler said:
Another thing i see is that your furnace is positioned wrong the vent pipe is way to long and has way to many elbows in it this will add to the buildup of creosote.
Click to expand...
This oil furnace will be replaced by the max caddy, it is last owner's installation... duct are also really badly installed... :- |
Thanks
 
David_QC said:
This oil furnace will be replaced by the max caddy, it is last owner's installation... duct are also really badly installed... :- |
Thanks
Click to expand...
Ok then
 
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