New Liner, Now Backdraft/Downdraft Problem

[Stoney Meadow Maple]

Just mentioning this, i was having all sorts of issues until i discovered that the top of my liner was floating about 1” above the top of my flue tile. Cold air coming down from the top on the outside of the liner caused all sorts of loss of draft, creosote buildup, and general strange behavior. I sent a camera down to confirm it wasn’t broken, and packed the top with fiberglass mat and high temp silicone. I am
Going to revisit it in the spring, but it made all the difference.
If you don’t have a good seal up there on the new liner it might explain something.

 

[mickey_g]

Just mentioning this, i was having all sorts of issues until i discovered that the top of my liner was floating about 1” above the top of my flue tile. Cold air coming down from the top on the outside of the liner caused all sorts of loss of draft, creosote buildup, and general strange behavior. I sent a camera down to confirm it wasn’t broken, and packed the top with fiberglass mat and high temp silicone. I am
Going to revisit it in the spring, but it made all the difference.
If you don’t have a good seal up there on the new liner it might explain something.

I had a similar problem which this was supposed to fix. A few years ago we had a dormer put on upstairs & had to raise the chimney 10' or so. When the mason crew did, they just extended the flue & put a cap on top without extending the liner inside. As you might imagine,after a few years we were wondering why there was that smell, draft and actually rain water coming down the chimney. The cement crown cracked & deteriorated, & whatever else they did while extending the chimney probably also had a similar fate. Well, now it's pretty much the same problem, but with a different cause. We had about 5 chimney people come for estimates that never showed up again, or even got back to us with a $$$ number. I live on Long Island and "reliable chimney companies" is almost an oxymoron. My wife & daughter found this guy at the trade show at Nassau Coliseum & apparently were impressed. That, and they actually showed up to do the work. I'll leave it at that.

 

[mickey_g]

OP here. Following up, I decided it was time to vacuum out the old Keystone & replace the catalytic combuster. I had to move the stove, which is @ 500 lbs, by using a floor jack to get it on a dolly, then roll it away from the hearth so I could get at the combuster. Anyway, the way these guys had installed the clearance pipe looked like Rube Goldberg supervised them. Weird angles, male ends where females belonged...it took me half the day to coax the pipes back together, using some Rube Goldberg techniques myself, I imagine. Finally got the pipes together & man, were they breezy ! It was quite windy Saturday, so I'm thinking I better get some heat resistant tape or something. Harbor Freight (I know) is nearby, so I got a roll of this heat resistant aluminum tape for $7, wrapped the connections really good & voila! a flick of my Bic & the flame was drawn up & into the firebox of the ice cold stove.

Now, the question is, could my taping of those two connections stopped this down draft problem ? I mean it's like night & day, the difference. It was 25° this AM when I opened the stove door expecting to feel a cold draft, but didn't. Fire started right up, no hint of smoke blowback.

 

[Hoytman]

Bingo!
If the house is warmer than the outside air, then typically there shouldn’t be an issue with that much cold air coming down the chimney…although there is some cold air going to come in until a fire is built, but left open long enough room air should warm chimney enough to stop even that little bit of cold air infiltration. Have to give the warm room air some time to warm that chimney.

If the house is cold all bets are off.

If you have smoke coming out of the stove because the chimney has cooled down to the point smoke rolls in, then that means somewhere in the ashes you have enough coals to produce smoke and heat…so find the coals…and add several big loosely wadded up newspapers and let them catch. They’ll provide instant quick heat to help the chimney draft better while quickly opening and closing the loading door adding small kindling, etc., etc., etc., until the fire is re-established.

 

[Todd]

Why did you have to move the stove to get at the combustor? Is it shoved way back into a fireplace? You can also remove the cat from the top exhaust. At least you got a good look at your liner connection.

 

[mickey_g]

Yeah, the top exhaust bolts/screws are rusted/frozen into the mounting plate & frame. Tried getting them out years ago. "Easier" to do it this way, I'm likely to cause irreparable damage with my skills 😅 We had the fireplace bricked in recently & the stove is exactly 17" away from it. The connection is two 90° rotating elbows at a maybe 65° angle to the bricks.