Earlier this year, I bought a display model 8000CF-Oak Heat n Glow direct vent fireplace from a local vendor to install in a new house under construction
The unit's vent has a eight foot or so vertical rise before makeing a right angle turn to go out a side wall, about 15 feet way. It is mounted in a false wall about 24" think (wall has room for book cases on each side of the fireplace)
It was intsalled by the vendor.
I have used if a couple of times after the install just to verify it opeated. Now that it's colder I have run it for a longer period.
If the unit is on for several hours at high heat flame with the forced air fan running and then turned off, after an hour our so, there is a bang much liked some in the fireplace has expanded thermally and then contracted.
1. Is this normal?
2. If not normal how should I proceed? Call the vendor back?