Liner touching flue tile
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Just looking for some reassurance on this again. I have a forever flex liner. It’s wrapped in insulation, which they obviously did at install. I have an exterior chimney with two clay lined flues. One is for the boiler (no longer used) and the other is for the fireplace. We have an insert. This is the flue the chimney liner goes up. As I initially stated, some of the liner touches the clay on the way up. The side towards the boiler flue. (Boiler flue is to the left of the wood stove flue, and the liner touches the left side of the wood stove flue). Just wanted to double check that this is within code.
Depends on how thick the insulation is, some installers will install a thinner insulation just to get one past you.
This is the interior lined chimney above the old Jotul 3 CB a few years ago. The Flir only shows it being 78 at that hot spot, so not super hot, but in the 66 degree room you could feel that. Cool to the touch with the Progress Hybrid, which puts the heat into the room and not the chimney. Haven't done the IR of that chimney with the Progress.
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FYI.
| To maintain UL Listing 1777, 1/2” of insulation between the masonry and the liner provides for zero clearance between the exterior of the chimney and combustible materials. As a result, 1/2” insulation kits will add about 1.5” to the outside diameter of the liner. To maintain UL Listing 1777, 1/4” of insulation between the masonry and the liner provides for 1” clearance between the exterior of the chimney and combustible material. As a result, 1/4” insulation kits will add about 3/4” to the outside diameter of the liner. |
As long as you have 1/2" insulation it is rated for zero zero clearance. Which means zero clearance to the inside and outside of the masonry structure
The insulated ss liner radiates a certain amount of BTUs at a given temperature which is then dispersed over the larger outside area of the chimney. Having an air gap between the insulation and terracotta doesn't change the overall BTU output.
Yes the chimney will get warm. The question is does it get hot enough to pyrolize the wood around it? With an insulated ss inside terracotta inside brick I would say that's very unlikely.
78 F is still what I would consider "room temp" even if your room is 66F, and the inside surface of the wall is going to be warmer than that but not by a lot. You need higher temps than that to be concerned. The testing has been done and this is why insulated liners have been approved for use in a masonry chimney with no clearance around it.
Yes the chimney will get warm. The question is does it get hot enough to pyrolize the wood around it? With an insulated ss inside terracotta inside brick I would say that's very unlikely.
78 F is still what I would consider "room temp" even if your room is 66F, and the inside surface of the wall is going to be warmer than that but not by a lot. You need higher temps than that to be concerned. The testing has been done and this is why insulated liners have been approved for use in a masonry chimney with no clearance around it.
Thank you all for your responses. I feel confident everything is good. Sometimes you just need a little reassurance when you have a fire inside of a box in ur home. I’ve been burning this liner for 12 years now. But every now and then something will pop up in my head that causes me to need some reassurance that everything is safe.
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