Drafting Problems / Chimney Cap?

Hi folks...

I've had a Jotul Castine for about 11 years. Located in family room in basement. Stove exhausts into a double wall stovepipe, makes two 45 degree bends to go through the foundation into an outside chimney, which is cinder block with a round clay insert (6", I believe). Not sure of the exact height, but goes up to the peak of the roof, two story house.

Always had some drafting issues, mostly when getting a fire started and waiting for the chimney to get warmed up. Sometimes I get some smoke in the room when starting up, opening up the basement windows usually helps.

This past weekend, though, had a problem I haven't had before. Part of it may be that the chimney needs to be cleaned (guy coming next week). It was very windy outside, and had a real hard time getting flow up the chimney. When the stove, and stovepipe, finally got hot, could see smoke coming out the chimney, but also had smoke coming in the house real bad when opening the stove. Also had smoke coming in from where the stovepipe is connected to the thimble going into the foundation. Got worse when the wind gusted outside.

Couple questions:

- I have a generic cap on the chimney. Will a cap like a Vacu-Stack help with the wind issues?

- If there are severe drafting problems, is smoke leaking through the stovepipe joints "normal", or does that need to be sealed up somehow? Or to ask another way, my assumption is that a good draft will always keep a negative pressure in the stovepipe relative to the room... is that true?

thanks

chimneylinerjames said:

First thing you should check is the height of the chimney. If your chimney is not high enough, it will not draft well enough, period. If the height is not a problem, I would try to warm up the flue first. Do this by building your pile of kindling and paper first, do not light it, but have it ready. The curl up a piece of newspaper and light it on the end and place it near the flue outlet on the stove, this will pre-heat the air in the chimney and start the draft. You can also do this in the clean out of the chimney. Try this first.

I would not recommend a vacu-stack cap. It would get blocked up with creosote and cause more issues.

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Thanks... I've pretty much done all of that. The chimney height is probably about 20'; in fact, we added to it a couple years ago. The newspaper trick doesn't help much, especially if there's already a small downdraft. I've also tried using a hair dryer to blow warm air up as well. The biggest problem seems to be when it's windy out, and even with the stove running at about 450 F with dry wood, there were moments when the flames would die down and smoke would fill the firebox when a good gust blew outside.

chimneylinerjames said:

When I said the height of the chimney, I am referring to the height of the chimney above the roof and other objects around it, such as trees. Wind issues can always be solved by raising the chimney. You have to get the chimney above the turbulence from the wind. So raising the chimney always helps.

What you can try just for a test, is as you are burning the stove and having the issue, go up to the roof and add on a piece of 6" stove pipe, maybe 4' long to the top of the chimney. This will just see if 4' will solve the issue and get it above the wind blowing down the chimney.

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Thanks for the clarification; that's not a bad idea to extend the chimney that way to see if that helps....

A1Stoves.com said:

90+% of the smoking stove calls i get end up being a clogged cap

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I believe it. I did get a pretty good look at the cap with binoculars.... it didn't look clogged... but I could only look at one side of it....

WellSeasoned said:

Castine here, although newer, but same concept. The most important question right now is WHEN WAS THE CHIMNEY CLEANED LAST? I am reading that the smoking issue is worse and that worries me.

What was the outside temp when you lit the stove?

How is your wood supply from a truly seasoned standpoint?
You have plenty enough length of chimney@ 20ft. The two 45's will hinder the smoke flow alittle, but shouldn't the way your explaining.

My castine spills alittle smoke once and awhile, but rarely. We have a straight shot up. During start up, smoke out the chimney, and it comes out the entire width if the chimney.

When the smoke is coming out of the chimney are you seeing it the width of the stack or skinnier than your stack?

Smoke should not be coming from the joints of the pipe. I worry about blockage in there.

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It was about 40 deg outside, plenty cold to run the stove. In fact, I last ran it when we lost power after Sandy, warmer outside, and it worked great. Haven't used it since then, which is why I'd be a little surprised that it would be a creosote issue... although we were running it not real hot towards the end.

The chimney was last cleaned about a year ago, have it scheduled to get cleaned again next week. The wood I have is seasoned at least a year (cherry, mulberry), didn't sizzle or bubble when put in the fire.

With the height of the chimney - and the wind blowing pretty good - it was hard to tell if the smoke was the width of the chimney or not...

In any event, I'm waiting until the chimney gets cleaned before I try again. I guess my biggest questions were about getting a cap that would help with the wind, and seeing the smoke leak through the stovepipe... never saw that before.

thanks....