Sealing behind an inset Electric Fire

[onebigcog]

Hi,
Am trying to install an inset electric fire.
The fireplace did burn coal, and then had a gas fire with a flue & box installed.
We have removed the gas fire and the box, leaving the flue.
I then put the electric fire in place, but we get a soot smell from time to time.
So, I pulled the fire out and fitted a standard flue box to seal it all up.
But the fire is a few mm wider and won't fit back in.
So, am looking for suggestions as to how to seal up behind the fire.

Stuart

 

[Wayners]

Clean off.
Cement render inside

Or

Dot and dab hardy backer board with cement based adhesive. Few screws and wedi washers. Not many.

Brick slips stuck on with cement tile adhesive or maybe tiles inside

 

[Ivor Windybottom]

I have one that's currently freestanding but you can remove its sides and inset it, as I was intending to do.

Unless I'm missing something, it looks like it actually draws air from the fireplace, heats it then blows it into the room. In which case I definitely will be looking for a different one.

Worth checking yours, see how it works.

 

[ree]

OP,
Why not post pics showing the fire box and the elec fire - & a pic of the fireplace after removing the fire box?
Has the flue been swept? Has the terminal on the stack been ventilated - flues need venting at the bottom & at the top.
By "sealing up behind the fire" I presume you now want to abandon the flue box, & then do whatever you mean by "sealing up"?
If sooty walls are present inside the fireplace opening then the sooty walls needs dry scrubbing clean before any sealing up.