furnace flue pipe temperature

[rhondas]

I have a mobile home with a kerosene furnace for the home heating hot air system , I want to add some sealant to the top of the flue chimney pipe that goes up through the roof inside the house, so what type or temperature silicone type of sealer do I use for this because the highest temp silicone sold in Ace hardware is 500 degrees ?

[Stytooner]

That outer pipe or shield should not get that high of a temperature. If it is doing that, something is wrong with the inner pipe.
Any regular fire stop sealant in a caulking tube should be fine providing there is no damage to the actual piping. Just simply apply as needed just like caulk.

[rhondas]

flue pipe temperature sealent

That outer pipe or shield should not get that high of a temperature. If it is doing that, something is wrong with the inner pipe.
Any regular fire stop sealant in a caulking tube should be fine providing there is no damage to the actual piping. Just simply apply as needed just like caulk.

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so ANY SILICON SEALANT THAT IS SAFE FOR 500 DEGREES IS OK, Sorry about the caps on , I guess the flue pipe doesn't get as hot as I thought , I figured at lease 1,000 degrees? Thank you for helping

[Stytooner]

It shouldn't get that hot, but if you are experiencing extra heat on the outer pipe, it might be time to test it. HF currently has the IR temp gauges on sale.
I have found quite a few uses for mine.

http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-69465-8905.html?utm_medium=email&utm_campaign=4813_black_friday_preview&utm_source=1020

It's on sale Fri, Sat, and Sun for $19.83.
It is a nice unit.
They have a cheaper flat version. I had that originally but it eventually failed.

That is inexpensive for your security. I am sure that a certain percentage of house fire statistics every year start right there.

[rhondas]

flue pipe temperature

It shouldn't get that hot, but if you are experiencing extra heat on the outer pipe, it might be time to test it. HF currently has the IR temp gauges on sale.
I have found quite a few uses for mine.

http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-69465-8905.html?utm_medium=email&utm_campaign=4813_black_friday_preview&utm_source=1020

It's on sale Fri, Sat, and Sun for $19.83.
It is a nice unit.
They have a cheaper flat version. I had that originally but it eventually failed.

That is inexpensive for your security. I am sure that a certain percentage of house fire statistics every year start right there.

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Thanks a lot Ill check into that and its not that the pipe is hot, I was just wondering what is the average temperature of a flue pipe that's about 4.5 " in Diameter and about 5 feet high into the roof ceiling ?

[Carpenter96]

Most mobile home furnaces draw their combustion air from out side. Generally the flue pipe that you see is actually the outer combustion air pipe and there is an inner pipe that is the flue pipe. This because of the closet that they are usually placed in.

Regards Bob

[Stytooner]

Right.
Air entering from outside between the pipes would actually help to keep the outer pipe cool.


Here is a link to some of the issues with this.

http://www.inspectionnews.net/home_inspection/attic-areas-home-inspection-commercial-inspection/32183-attic-insulation-around-furnace-flues.html

Pretty good discussion on it.

Still not a bad idea to actually test the temperature yourself.

Mine is an LP unit that is almost 20 years old.
That is pushing the life expectancy I think.
It will be replaced with something updated for next season and all parts will be replaced. Not just the furnace.

[rhondas]

flue pipe

Most mobile home furnaces draw their combustion air from out side. Generally the flue pipe that you see is actually the outer combustion air pipe and there is an inner pipe that is the flue pipe. This because of the closet that they are usually placed in.

Regards Bob

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I was wondering if this is what you call a double insulated flue pipe when there is 2 walls inside ?

[Stytooner]

I think mine is the same. The flue inside the furnace is a small pipe and does get warm, but where it exits the furnace cabinet, it is surrounded by a much larger pipe. Maybe 8" diameter. That is what goes through the roof. The large pipe is seen on top where the vent cover attaches, but it attaches to the inside or flue pipe first, then just secured on the outer pipe band.

[rhondas]

flue pipes

I think mine is the same. The flue inside the furnace is a small pipe and does get warm, but where it exits the furnace cabinet, it is surrounded by a much larger pipe. Maybe 8" diameter. That is what goes through the roof. The large pipe is seen on top where the vent cover attaches, but it attaches to the inside or flue pipe first, then just secured on the outer pipe band.

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from what I can see on mine it a 2 elbow turn then straight up about 3 feet into the ceiling, and some silicone sealant around the pipe , so if it has a larger pipe on the roof or through the roof I would have to get up there , how ever from out side looking at the roof the chimney stack and cap on the roof looks at least 8-10 inches in diameter.

[Stytooner]

Sounds like it may have triple walls on yours at the top.
Mine has only two that I am aware of, but may actually have an extra shield while inside the furnace and then exits through there into the ceiling with the large diameter vent.
No turns or elbows on mine.