Sealing air gap between sheet metal surround and brick hearth face

[J.Stempel]

Our Jotul 550 was installed about a month ago, with a black metal surround that fits nicely around the remaining fireplace opening and extends about 2 inches overlapping the brick face of the surrounding hearth.
Before we did this, in summer the fireplace creosote residue would stink the house up if we didn't tape a plastic sheet inside the fireplace as air would draft back into the house depending on pressure and temp gradients. I was hoping the insert install would eliminate this, but now find that air is still back-drafting into the house through two areas (maybe more) - the vent that blows hot air into the house from the Jotul when the fan is on, as well as the small 1-3 mm air gap between the sheet metal surround and the brick face.

After stuffing some towels in the vent above the door about 80% of the problem is gone, so I suspect I'll fashion a piece of sheet metal to attach to this area in between uses that accomplishes the same seal with some fireproof insulation.

My question to the forum is whether it makes sense to run a bead of fire rated caulk between the surround and the brick face as well. In the even we needed to remove the stove it would be easy enough to slice through it.

Any thoughts?

Thanks.

 

[webby3650]

You shouldn't need to seal around the surround. The smell isn't coming from the blower, instead it's coming down the flue and out through the primary air. Is the air control all the to low? That will help.
Did the entire fireplace get cleaned before the stove and liner was installed? Also, is the top completely sealed? It should have a top plate that is sealed down with silicone. If it's sealed good at the top, you could plug the flue at the top to stop the downdraft. Just put a note in the insert so it's not forgotten.
With the top sealed and the air control on the lowest setting, the smell should be minimal, but it still happens sometimes.

 

[J.Stempel]

I appreciate your input. Though I'm not sure I totally understand, I will make sure that the air control lever is all the way to it's lowest setting.

As far as the blower, assuming we are talking the same thing, I'm referring to the 1 inch high opening above the firebox and door that blows air when the fan knob is turned on. I have assumed that draws air from a source behind the stove within the original masonry fireplace because anytime I turn that on I immediately smell creosote-tinged air until the stove heats up. So the air intake opening can't be from inside the room but rather must be behind the stove. Unfortunately the manual really does not show this as far as I can see.

As well, as soon as I plugged this area the smell dropped off dramatically.

In the photo, the sheet metal surround can be pulled back slightly and you can see right into the old fireplace, not surprisingly, so I was mainly trying to understand if there was some other way that air from within the fireplace could escape through the actual Jotul unit.
I did clean the fireplace as best I could but by no means was it creosote-free at install time.
Thanks.

 

[webby3650]

Do you have a full liner that is blocked at the top?

 

[J.Stempel]

Yes, they did a pretty thorough install as far as the liner, etc. Also have a cap and screen from the original chimney/fireplace days.

 

[Don2222]

Our Jotul 550 was installed about a month ago, with a black metal surround that fits nicely around the remaining fireplace opening and extends about 2 inches overlapping the brick face of the surrounding hearth.
Before we did this, in summer the fireplace creosote residue would stink the house up if we didn't tape a plastic sheet inside the fireplace as air would draft back into the house depending on pressure and temp gradients. I was hoping the insert install would eliminate this, but now find that air is still back-drafting into the house through two areas (maybe more) - the vent that blows hot air into the house from the Jotul when the fan is on, as well as the small 1-3 mm air gap between the sheet metal surround and the brick face.

After stuffing some towels in the vent above the door about 80% of the problem is gone, so I suspect I'll fashion a piece of sheet metal to attach to this area in between uses that accomplishes the same seal with some fireproof insulation.

My question to the forum is whether it makes sense to run a bead of fire rated caulk between the surround and the brick face as well. In the even we needed to remove the stove it would be easy enough to slice through it.

Any thoughts?

Thanks.

You really need a Damper cut-off plate with fireproof Roxul Insulation above it!
See video on how to make one.
https://www.hearth.com/talk/threads/making-a-fireplace-damper-cut-off-plate.110230/#post-1458336