Harmon pf100 smoking fix

[Rattlesnake]

Something to watch for on Harmon pf100. Installed 4 weeks ago, and after initial burn-off, smelled wood smoke rising thru the registers into the second floor bedrooms and at the top of the basement staircase upon startup. No smoke could be detected from the pipes or the unit. Installer returned, pulled off the vent pipe where it connected to the furnace and also removed the panel that covers the handle to the chain shaker. With the panel removed, you can look up at the bottom of the vent outlet and see that it is neither welded nor sealed at the factory. This allows exhaust smoke and gas to be sucked back into the outer chambers of the furnace and into the house. He reached in and sealed the bottom with silicone caulk, then sealed the top as well before replacing the vent pipe to the furnace. It is a very tight space to work in. He claimed this is the second or third pf100 that he has had to seal in this area. Started it up and, so far, no smoke smell, and stove flame is much more consistent as well.

This may be something future purchasers want to inspect prior to installing the plenum and ductwork....while the bottom of the vent connector is easily accessible. Hope this works for us and may be of help for some others.

 

[hailfire]

Your post came in at a handy time.. Just had my PF100 installed and waiting for ductwork to be installed.
It was much easier to seal that space with high temp silicone compound with the supply duct still open.

Thanks!

 

[exoilburner]

Rattlesnake, same thing happened to my PF100. Smoke smell out of the house heat registers. The dealer kept telling me to seal the vent joints they must be leaking somewhere. I found the gap between the furnace vent collar and the furnace cabinet the hard way. But after sealing it up with silicone.....no more smoke smell in the house. What a relief. I was beginning to think There was a bad weld in the fire box.

Nice explanation of the problem too.