Wood stove insert - drafts backwards when no fire

[Minihoser]

Hi
Moved into home last year with wood burning insert. No problems, ran fires daily and into spring.

Ran a few fires this year and the following day when fire is out draft seems to reverse. Hole in fire place where air should draft in are blowing air out into room. Can smell the ash. I tested with smoke and a lighter and can see entering room. Worried about fumes. Evening time draft is normal and can light fire. Days have been warm with low humidity. 70s during day. 40s at night. Sun comes out and starts to warm around 10 am, same time as draft reversal.

A frame house chimney liner runs up mason chimney. Liner looks to be corrugated. It is oval through stack for 6 feet. Total chimney liner length is 25 ft and sits 4 ft above top of roof.

Thanks
Jason

 

[bholler]

Hi
Moved into home last year with wood burning insert. No problems, ran fires daily and into spring.

Ran a few fires this year and the following day when fire is out draft seems to reverse. Hole in fire place where air should draft in are blowing air out into room. Can smell the ash. I tested with smoke and a lighter and can see entering room. Worried about fumes. Evening time draft is normal and can light fire. Days have been warm with low humidity. 70s during day. 40s at night. Sun comes out and starts to warm around 10 am, same time as draft reversal.

A frame house chimney liner runs up mason chimney. Liner looks to be corrugated. It is oval through stack for 6 feet. Total chimney liner length is 25 ft and sits 4 ft above top of roof.

Thanks
Jason

This is pretty common and not allot that can be done about it.

 

[Rickb]

If mine does that I reverse it with a blow torch then light a candle in it. Ussually keeps it ok. The warm days of the shoulder season can cause some weird draft issues.

 

[sardo_67]

If mine does that I reverse it with a blow torch then light a candle in it. Ussually keeps it ok. The warm days of the shoulder season can cause some weird draft issues.

YUP!! I use a click on MAP plumbing torch to start my fire as well as get the draft going the right way. I’ll turn that on and point it up the chimney to get it going the right way. Then toss in a 6x6 piece of cardboard to start and check the draft is going the right way. If it is I’ll quickly put in the kindling and small stuff then put the torch on it to get it going.

 

[begreen]

Things should improve as it gets colder. Make sure there are no windows open on the floor above and attic vent (if there is one) is closed and sealed. Make sure you have a good quality and functional CO monitor/alarm in the fireplace room

 

[brazilbl]

Another idea is to check and see if you may have the clothes dryer/kitchen/bathroom exhaust fans going that might contribute to the reverse draft.

Had *that* happen to me one evening last year. Found out the clothes dryer was on so I shut it down and started the fire. Turned on clothes dryer *after* knowing that the fire was sustainable...