Smoke puffing out of top of stove

[switchbackvt]

We have an mid-2000s Hearthstone Mansfield that, for the past two weekends, has been puffing smoke out of the top of the stove. I'll be running it all day, medium to hot (flue temp reads 350ish), and then I'll tamp it down a bit for the evening when we're getting ready for bed. About 30 minutes to an hour later, the house will be filled with smoke because it'll start puffing smoke. It will appear that smoke is going up the chimney and then it will cough a puff of smoke into the house. Any thoughts on why this happening? Best way to remedy it?

We've had issues with drafts in the house - even when the stove and logs are hot, smoke will come into the house - and last winter (it was so bitterly cold) we had to clean the chimney twice because of creosote. We're burning last season's wood, so it's been sitting for a year and a half.

Thanks!

 

[merc525]

Interesting that I found your post tonight, I just came home and found my house full of smoke with smoke puffing out of my woodstove.This is the second time this has happened and am also looking for an answer

 

[begreen]

This sounds like a puffback. Are you adding wood before tamping it down? Normally this happens from closing down the air too far, too soon. The fire dies and the firebox fills up with wood smoke that ignites with a small explosion when a flame reappears.

 

[merc525]

This sounds like a puffback. Are you adding wood before tamping it down? Normally this happens from closing down the air too far, too soon. The fire dies and the firebox fills up with wood smoke that ignites with a small explosion when a flame reappears.

Thanks for your reply, the smoke problem happened again tonight, I left my house with a seasoned fire burning and came home 2 hrs later to find smoke in the house. This is a stove we purchased and used all last year with no problems. I guess I don't understand how an air tight stove can introduce smoke into my house.

 

[firefighterjake]

A) Because it is not truly an air-tight stove

B) Because in a back puff situation smoke will find its way out of every little crack and crevice in the stove (sometimes joints, gaskets, incoming air, around stove air controls, etc.) and chimney and chimney connectors.

 

[BrotherBart]

If the burn is settled in, after an hour or so from loading, and this is happening something is big time wrong here. Air tight is a term for stoves from the 80's. These stoves have breathing holes in several places. Those can also be belching places.

 

[Jazzberry]

Mine did a little it when my spark arrestor got plugged up.

 

[fire_man]

The two things I would look at:

First check for a Plugged cap like Jazzberry said.

Then I would consider you might have a chimney draft issue. How tall is your flue?
I had a similar backpuff problem and added 2 feet to the stack to cure it. These mild temps are draft killers.

 

[webby3650]

When you cleaned the chimney, did you pull the stove pipe and vaccum out the flue collar as well as the area above the baffle?

 

[axeman628]

If it worked great last year and it started smoking this year, something changed. Check the chimney, flue and look for anything limiting air flow in the stove too. Something has to be affecting your draft.