Shared Furnace/Fireplace Flue

[Jerry Simon]

Should a decorative gas appliance (a pre-fabricated metal fireplace with a gas log-set) flue pipe vent/tie-into a draft-induced furnace's metal B-vent?  I'm pretty sure this isn't okay as combustion fumes from the furnace could potentially draft back into the dwelling through the fireplace.

Thanks.

[Marc]

According to chapter 13 of NFPA 54 (fuel gas code), they can be joined but only in compliance with that chapter.

Edited February 22, 2018 by Marc

[John Kogel]

I'd call it out, because chances are good it doesn't comply with Marc's rule.