Positive, Negative Pressure I have tried Everything

[elconquistador]

Sorry to be a long message but wanted to ensure I covered everything.
Positive Pressure, Negative Pressure, Down Draft, Back Draft. I have read way more on these subjects than I have ever wanted to and still do not have a solution for why smoke is coming in when I open my fireplace door.

First time poster here. I have been the owner of a fireplace insert fireplace for two years now. First winter I had no issues with smoke coming into the room, even with the door all the way open. This winter I didn’t have any issues until about 3 weeks ago. It has gotten so bad that when I open the door the smoke rushes into the room and can fill it up in a matter of just 2-3 minutes if I was to allow that to happen.

Fireplace burns great with the door shut or open to approx. 1-3 inches, no smoke will enter the room. Once I start going beyond the 3 inch mark is when it will start to come into the room.

Fireplace is a Kozy Heat Z-42 Zero Clearance Factory Built Fireplace

Here is what I have done but has not solved my problem:
Burned Creosote Log
Cleaned the Chimney
Tried to reestablish positive pressure using many, many different methods;
Heated the flue up, cracked window near fireplace
Started a really hot fire fast, crack window
I Burn seasoned wood only (I have a wood meter and I split then measure everything)
Smoke is coming out of the chimney top

When I have the door shut I can see the smoke roll from the top front of the fireplace down. This would indicate a negative pressure, but I can’t seem to reverse it no matter what I do. I wouldn’t think it would be that difficult to restore positive pressure. My last resort is to have a fan installed on the outside but do not want to do this yet.

The only other thing I can think of is when cleaning the chimney if I damaged something in the process. I will need to run a camera up to see if this is the case but I don’t think it will be the case. Any other suggestions?

 

[firefighterjake]

Common sense would say that if things ran well last year and ran well until just three weeks ago, something happened right around that time that has caused this issue.

Typically the most likely cause I would guess would be a draft issue caused by some sort of blockage. If the chimney and cap were cleaned top to bottom the next thing I might look for would be to insure there is not a build up of ash in the smoke's pathway from the firebox to the flue. I know with my woodstove in the annual cleaning I make a point to clean out the ash above the baffle as one year there was a lot of ash which had blocked off maybe half of the flue's exit -- not enough to be a problem for me as I have a strong draft, but it was enough for me to realize it should be checked yearly.

 

[bholler]

I agree with everything ffjake said there. But want to add to it. Has anything else changed in the house during that time?

New windows
New bathroom fan
New kitchen exhaust hood
Attic door open or leaking
Etc

 

[kennyp2339]

With the fireplace door shut you should see it roll down, thats the airwash doing its thing
If the wood is dry, chimney clean, cap is clear then the next suspect would be the baffle, some inserts have a plate, some have boards the rest on the air tubes, some have firebrick w/ a blanket on top
If you have boards that rest on the air tubes then make sure the pushed to the back of the stove, if you have one with a blanket on top make sure the blanket is laying flat and not bunched up or pulled forward.

 

[bigealta]

Sounds like a blockage. Did you check the cap? And the top of the stove between the flue pipe connection and where the smoke leaves the inside of the firebox, like Kennyp describes.