Help with lining a oil furnace chimney

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Fliptop454

New Member
Jun 24, 2019
3
39
Hello all,
I'm currently researching how to line my oil furnace terracotta 8in by 8in existing chimney with a stainless steel liner. I'm hoping that I can gain some information and tips about the best way to go about this. I have some initial questions but I'm open to all pieces of advice.

1. What is the best liner to use for a oil burner furnace exhaust. Meaning should it be a double wall stainless steel or is single wall acceptable?

2. For an oil burner and the fact that this is going to be a tight fit if I use a 6 in liner can I get away with not using a wrap around insulation on the liner?

3. Do I need a T-body for the bottom of the chimney or should the liner just begin to pitch on a 45 and come out of the cinder block wall near the furnace?

4. Last question... I have one challenge that I'm going to face for sure when pulling or pushing this liner down to the basement. That challenge is a piece of terracotta tile that is slightly shifted about a half an inch to 1 inch out of line from the rest of the tiles. Has anyone had to face a similar challenge and was there any tip on how to best overcome this obstacle?
 
Hello all,
I'm currently researching how to line my oil furnace terracotta 8in by 8in existing chimney with a stainless steel liner. I'm hoping that I can gain some information and tips about the best way to go about this. I have some initial questions but I'm open to all pieces of advice.

1. What is the best liner to use for a oil burner furnace exhaust. Meaning should it be a double wall stainless steel or is single wall acceptable?

2. For an oil burner and the fact that this is going to be a tight fit if I use a 6 in liner can I get away with not using a wrap around insulation on the liner?

3. Do I need a T-body for the bottom of the chimney or should the liner just begin to pitch on a 45 and come out of the cinder block wall near the furnace?

4. Last question... I have one challenge that I'm going to face for sure when pulling or pushing this liner down to the basement. That challenge is a piece of terracotta tile that is slightly shifted about a half an inch to 1 inch out of line from the rest of the tiles. Has anyone had to face a similar challenge and was there any tip on how to best overcome this obstacle?
You want single wall liner light wall is just fine for oil or gas. It needs to be 316.

Liquid fuel does not need to be insulated but it does help reduce condensation.

Yes you need a tee

It may go down easy or may not fit at all with the clay in place.
 
Bholler,
First and foremost... thank you your responses were very helpful.

Two more questions...
1. A co-worker of mine also lined his chimney but for a different purpose as he has a wood-burning stove. He had an entirely different experience than what I expect to have. He basically said his liner pretty much just fell right down the chimney while installing. I definitely do not expect to have that kind of room. He was also able to put a wrap around insulation on the stainless steel liner. As added insulation he stuffed some fireproof insulation in the voids between the Terracotta and the liner. I was thinking to avoid condensation buildup of trying to do the same obviously minus the wrap around insulation blanket. Though I do not expect to have much voided area even without the wrap around insulation blanket. Do you think it is worth attempting trying to push several torn up pieces down the voided chimney area betwen the new liner and the old terracotta flue tiles? I ask because i expect that i will be sealing the chimney cap to the terracotta and would hate to have to open that up again.

2. Last question seeing as how the 6 inch liner's true diameter is about 6.25 in and having some shifted terracotta flue tiles will mean I have a very tight fit in at least two spots. In order to combat the struggle that may ensue do you suggest using a pulling cap to help pull down the liner if I cannot push? To elaborate what my concern is is that without a wrap around insulation blanket on the liner I fear that the pipe will not be rigid enough to push straight down. Am I wrong in assuming that?
Thank you again for your response and knowledge it is much appreciated!
 
Last edited:
Bholler,
First and foremost... thank you your responses were very helpful.

Two more questions...
1. A co-worker of mine also lined his chimney but for a different purpose as he has a wood-burning stove. He had an entirely different experience than what I expect to have. He basically said his liner pretty much just fell right down the chimney while installing. I definitely do not expect to have that kind of room. He was also able to put a wrap around insulation on the stainless steel liner. As added insulation he stuffed some fireproof insulation in the voids between the Terracotta and the liner. I was thinking to avoid condensation buildup of trying to do the same obviously minus the wrap around insulation blanket. Though I do not expect to have much voided area even without the wrap around insulation blanket. Do you think it is worth attempting trying to push several torn up pieces down the voided chimney area betwen the new liner and the old terracotta flue tiles? I ask because i expect that i will be sealing the chimney cap to the terracotta and would hate to have to open that up again.

2. Last question seeing as how the 6 inch liner's true diameter is about 6.25 in and having some shifted terracotta flue tiles will mean I have a very tight fit in at least two spots. In order to combat the struggle that may ensue do you suggest using a pulling cap to help pull down the liner if I cannot push? To elaborate what my concern is is that without a wrap around insulation blanket on the liner I fear that the pipe will not be rigid enough to push straight down. Am I wrong in assuming that?
Thank you again for your response and knowledge it is much appreciated!


1. no it absolutely isn't worth trying to stuff insulation down around it. For an oil furnace pour in insulation can help enough to keep condensation down inside the liner.

2. If you have offset joints it is very possible the liner will not fit at all. And no you can't force it down if it doesn't fit. It will just get stuck and you will be screwed. The clay tiles may need to be removed.
 
Bholler,
Sorry to bother you again.... I have one more question. I read (but now cant find the blog anymore) that after connecting the tee- body to the snout i should seal the meeting point between the two. What do you suggest to use at this point? I am assuming a high heat sealant but would imagine it must be from a squeeze tube or caulk gun? Not sure if it should be a high temp silicone that usually is only good to 400-500 degrees or something more like refractory cement that is good to much higher temps?
Thanks again
 
Bholler,
Sorry to bother you again.... I have one more question. I read (but now cant find the blog anymore) that after connecting the tee- body to the snout i should seal the meeting point between the two. What do you suggest to use at this point? I am assuming a high heat sealant but would imagine it must be from a squeeze tube or caulk gun? Not sure if it should be a high temp silicone that usually is only good to 400-500 degrees or something more like refractory cement that is good to much higher temps?
Thanks again
Follow the liner manufacturers directions