Sealing vent pipes.

Congrats on the new stove. I sealed all the inside vent pipe sections. I also sealed around the vent pipe to the thimble with the same high heat silicone I used on the pipe. worked great.


Shawn

If you used Dura Vent Pellet Vent Pro you will need to seal eash inside the house joint with heat rated silicone. If you used the Dura Vent Pellet or Corn Vent you will have to seal each inside joint and at your option use screws no longer that 1/4". The gap in the thimble can also be sealed with the same silicone or just leave it alone. Eric

I also have a 25-PDV and aluminum tape was used for the inside joints by the installer rep.
The pipes outside just have small screws, no silicone except for the thimble on the siding....

Alum tape would be pretty freaking ugly inside the house. We seal all the joints with black silicone on the inside of the pipe. Also seal the thimble passage with the same silicone. Yes it is true Simpson says you don't have to seal it. I talked to a Simpson rep about smoke leaking and he said many pellet stoves use more powerful blowers than the min specs they are required to test the vent at, so that can make smoke leak out. He said if the manufacturer of the stove says to seal all the pipe joints that it would be a good idea.

You are talking about the gap between the radius of the thimble and the outside of the P vent pipe right? That doesn't really get hot but just lets in cold air. You should be able to get away with any sealant back there but the twist joints are to be sealed with the red hi temp silicon you can get a t Auto Zone. Don't forget after you get it on there if its out in plain view you can wipe most of it off and the joint will be sealed and not be so visible. The only one I sealed on mine was the single one between the outlet of the stove and where it goes through the thimbal as mine is very close to the wall. Come to think of it I believe they do make a black silicon which has the same basic heat rating as the red stuff and looks better.

I used sealant inside the pipes that are on the inside of the house. I had a small leak out the back of the 45 elbow so I also used a rubber-like silicone tape that I read about here on all inside joints. Its about an inch wide and can be found in the plumbing section of your hardware store. It is a cloudy color so it looks fine against silver pipe. It stays on fine and works great. You may want to seal the outside thimble gap to keep the water out.

rmac said:

Thanks for the replies.

I'm not too concerned about how it looks because you have standing on top of the stove to see the pipe. That being said, which do you think is better, silicone or tape?

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Red hi temp silicon sealer without a doubt. Advance or Auto Zone both have it in a small toothpaste tube size for a few bucks They use that stratight without a gasket on major assemblies on Caterpillar tractors and I know for certain they seal the differentials the same way on Chrystler products the same way. Put some on the male part of the pipe and just twist it together and its sealed to perfection. If you can't get it apart without a hassle then I would just make a bead all around the mating surfaces where they come together and call it good. Its not like you are holding against liquids under pressure or anything like that. If for some reason it still leaks you can always separate and reinstall if need be.
Don't be surprised if much of your smoke problem arises from your opening and closing the door. Mine will throw a large puff of corn fallout out with the blower from the ridge in front of the air wash where it meets the glass if I don't crack the seal give it a 2 count then open the door slowly. You might or might not have something similar going on, just keep an eye out when you open the door, if its there you should see it.