chimney plug

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Charles2

Feeling the Heat
Jun 22, 2014
281
GA
For the off season, can y'all recommend a durable, airtight plug for a 6" diameter chimney?
 
Old bath towel, wad of fiberglass batt insulation, etc. Just leave a nice note for yourself (or your next of kin) in the stove, so you don't smoke out the house when lighting that first fire in the fall.
 
There are all kinds of things made. Are you trying to seal the top or from the bottom?
 
If you disassemble things you could use a tee cap but the easiest is just to stuff something in there. For cleaning we use a trash bag stuffed with insulation. But really in most cases there is absolutely no need to seal it off anyway
 
Be sure to leave a large note in the firebox warning to remove the plug be for firing again.
 
If you want a good cap with a decent deal you can use a Jim cap. It's a rubber cap with a 5/16tightening nut. They are usually used as temporary caps on waste pipe. Not sure if Home Depot / or basic hard ware store would have one but any plumbing supply shop would.
 
Unless your chimney back-drafts smoke smell into the house, mostly only an issue with basement installs, why would you want to plug the chimney in summer? Shut the stove doors, close the air control, and relax.
 
If you want a good cap with a decent deal you can use a Jim cap. It's a rubber cap with a 5/16tightening nut. They are usually used as temporary caps on waste pipe. Not sure if Home Depot / or basic hard ware store would have one but any plumbing supply shop would.

I've heard plumbers call them Fernco caps. But I want a plug, not a cap.

There are all kinds of things made.

Such as?
 
Be sure to leave a large note in the firebox warning to remove the plug be for firing again.

The bucket of DampRid I leave inside the stove also serves as a plug reminder.
 
I would use a plain toy balloon. Cheap, will do the job and will pop if somebody lights a fire.
 
I dont see why you need to seal it anyway do you get down drafts?
 
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Plumbing balloons come in 6" just don't over pressure the balloon against the pipe or you could blow out the pipe. http://www.oatey.com/products/pneumatic-test-balls/test-balls/multi-size-test-ball-plugs

Those are intended for short term tests. I want this to seal for months.

I would use a plain toy balloon. Cheap, will do the job and will pop if somebody lights a fire.

Definitely not a long term solution.

I dont see why you need to seal it anyway do you get down drafts?

What we all need is to be as energy efficient as possible.
 
I get bit of dampness on the floor of the stove. Those summer blowing downpours get under the screenless cap. Also in the spring I get blue birds. My plan was to drop a 5 gallon bucket over the top, but never did. I wouldn't want to plug it up with a balloon. It would restrict the air flow that would dry it out.
 
What we all need is to be as energy efficient as possible.
And how will plugging the pipe during the summer help with that?. Really you will have little to no air moving through the stove if you close it up. Believe me you are worrying about another problem that does not exist. And like xman said that tiny bit of air movement is not a bad thing.
 
If that were true, the stove would not burn at all when the door is closed and the damper is shut. But it obviously does.
That is because the heat differential causes draft with out that heat differential there is no draft. That is why you had trouble establishing draft when it was warm outside. You do realize that to tight a house in the summer can cause lots of issues. And besides if you are pushing being as energy efficient as possible do what i do in the summer and open the windows then that tiny amount of air moving through the stove wont matter in the least.
 
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If that were true, the stove would not burn at all when the door is closed and the damper is shut. But it obviously does.
I work in and around stoves and fireplaces every day. In the summer even with the door and damper wide open there usually is very little air moving thought the chimney at all. If you really want to do it go ahead the only problem it can cause in condensation in the stove and chimney which can slightly shorten their lifespan. but it really is unnecessary unless you are getting bad down drafts
 
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why would you want to plug the chimney in summer?
I've been blocking the liner at the top for the last several years. On a hot day, the stack effect of the house draws warm, humid air down the chimney and it condenses in the stove...more so if you run AC and the stove is cool. You don't want water in your stove; It will rust. Granted, probably not a lot, but I don't like the idea. Now, on my soapstone stoves, the creo/water would seep out around the edges of the stones and leave stains, which I would have to remove with steel wool. I block it off, then I can really relax. ==c
 
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