Harman XXV suddenly making fumes

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JohnCC

New Member
Mar 5, 2026
1
New Hampshire
We have a Harman XXV that is at least 18 years old. Last night it started to stink up the room. There was no obvious smoke coming out, however, the connection at the back is deep in the fireplace and not all that visible. I looked back there with a flashlight and didn't see any smoke, and stuck my hand back there feeling for jets of hot air, but, again, nothing.

This AM I cleaned the stove. It was over due (ash pan overflowing.) I have a cleanout where it connects to the 4" chimney liner which I also cleaned. Unfortunately. after running about 2 hours the fumes became objectionable again.

One thing I noticed when cleaning was a bunch of what looked like caulking, pieces about an inch long and 3/8 inch wide, rectangular in shape, on the hearth under the stove. Could there be some sealant that has failed? Any other ideas?

TIA,
John