I just had a new power vented water heater installed (HTProducts Phoenix Light Duty) in our crawlspace. The contractor that put it in used part of the existing 3" concentric vent from the furnace we ...
We have a gas fireplace venting through the roof of our attic bedroom; there's a cap on a chimney up there. Double-wall construction, such that it pulls combustion air in from outside. When the wind ...