Downdraft on cold insert - weather?

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Pertzbro

Feeling the Heat
Aug 2, 2016
330
NW Iowa
Remind me again the weather conditions that would cause a downdraft on a cold stove/insert? I've lit 3 or 4 balls of newspaper in the baffle opening and get the draft reversed with the "jet" engine sound, only for it to reverse again later on.

We're currently experiencing heavy freezing fog and a front moving in to bring some rain/freezing rain/sleet and 5-10inches on snow. Wind is minimal if any.

No exhaust fans on other than the typical furnace.

Needless to say i'm going to buy one of those small torches to reverse the draft easier and without smoke.

Thanks,
 
Reverse draft is typically a result of the stack effect. Inside temp, outside temp, wind direction and other conditions effect as well. Where is the stove installed in the house?

Reversal after establishing draft is a concern if it happens when you have a load of coals. The amount of heat going up stack is minimal so flue temp drops and allows air to come down the chimney. You could end up with CO in the house. Got a CO detector located close by?
 
I have one in the bedroom. It only reverses again while still not in use. Never had a draft problem when I was actually burning. Only when cold.

Insert is a north facing exterior with 25foot of pipe. Only happens every now and then when atmospheric conditions seem to force it.
 
Hit the kindling and paper with a torch and hopefully it will warm up fast enough to get a proper draft going.

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Let me be clear. I'm not lighting a fire. Stove is cold and will remain cold. Just dont want the creosote/smoke smell pouring into the living space.

I did buy a benzomativc today. But again, I'm talking about having a reverse draft on a day or night when i dont plan on burning.....

I can reverse a draft and get a fire going no problem. It's when i have a reverse draft pouring bad smelling odors into the house and getting it to reverse correctly WITHOUT having an actual fire.
 
Do you have roof top picture it’s possible your chimney is not tall enough twin chimney caps or near by trees trying to redirect the air. Try opening or cracking a window
 
They do have a chain operated top plate to block air also when not in use
 
May be due to stack effect in your house. Check in the upper floors' ceilings for any place air can escape, making a "chimney" of your house; Light fixtures leaking air into the attic, attic access panel, leaky upstairs windows, etc.
 
? Stack effect without a fire can cause this
 
? Stack effect without a fire can cause this
Yes, the stack effect of the house itself; Warm air rises and escapes the upper levels of the house. If it is strong enough it can pull air down the chimney resulting in creo stench in the area of the cold stove.
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Thanks I’m learning
 
Edited my post to add cold stove,where the chimney has no draft. Sealing the light fixtures and attic access is something I need to do here. I don't get a reverse draft, but I need to keep as much heat in as possible to counter the effects of no wall insulation and some air leaks around electrical outlets, etc.
 
Let me be clear. I'm not lighting a fire. Stove is cold and will remain cold. Just dont want the creosote/smoke smell pouring into the living space.

I did buy a benzomativc today. But again, I'm talking about having a reverse draft on a day or night when i dont plan on burning.....

I can reverse a draft and get a fire going no problem. It's when i have a reverse draft pouring bad smelling odors into the house and getting it to reverse correctly WITHOUT having an actual fire.
If you dont want a fire you need to plug up that liner somehow. No matter what you do the draft is just going to reverse again as soon as the chimney cools down again.
 
Just some thoughts, maybe someone more experienced can verify or not...

Would leaving the air in the insert wide open, it alternatively (and a more aggressive measure) leaving the door cracked open help? The idea being allowing more warm air to escape up the insert thus keeping flue warmer and creating less chance for a draft reversal?

Not the most energy efficient but might be worth trying.
 
I don't think so. If the air wants to come down, it will just come down faster with the stove open.
 
I've used a shopping bag stuffed with newspapers to block the flue opening in the stove.
Just don't start a fire without taking it out, lol.
 
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I've used a shopping bag stuffed with newspapers to block the flue opening in the stove.
Just don't start a fire without taking it out, lol.

Yah, a big 'ol towel stuffed up there, and leave part of it hanging down so you see it before your next fire.