proper venting of furnaces and hw heater
So, I am helping put in a deck at my friends row house in Jersey city, and he had a major remodel done by a cheap contractor who cut a lot of corners, One of the biggest problems is the heating units, Two hotwater heaters and two boilers for forced air where put into a small shed attatched to the building. The shed will be under the deck after it is completed. The shed has no door yet, and the two boilers are vented out 2.5 inch PVC pipe that is extends out of the wall. The hot water heaters ARE NOT VENTED at all and have been an issue with the city inspector. The contractor is supposedly coming back to vent the hot water heaters up the wall.
The stub pipes for boilers will be under the finished deck, and I am wondering if I need to extend them, and I am also wondering if I can drill a hole in the roof of the shed, flash it and vent the hot water heaters through a PVC pipe to the roof of the building?
Replies
You need to get and read the manufacturer's instructions for venting these units. You need to get and read the code regarding combustion air for gas-burning appliances when they're enclosed. A typical storage hot water heater? Nope, can't vent that thru PVC. The boilers may be HE condensing types and vent/drain condensate thru PVC, but don't assume all flues are PVC. Yes, you can vent thru the roof, it's done all the time.
it seems like the guys who where there before me where real knuckleheads, and given the choice between done right and done cheap, they picked cheap... is it ok to have the flues from the boilers venting under a deck or should I extend them to beyond the edge of the decking
I don't know the mechanical code well enough to answer that. I once had a pair of high efficiency furnaces vented at edge of a raised porch, so that if you were standing at the railing you could look down and see the outlets. That passed inspection, but the mechanical guy who did it was in charge of making it right. As far as I know the code relates mostly to proximity to doors, windows, property lines, etc. I'd be surprised if UNDER the deck is OK, but it probably is if you bring it to the edge of the deck. Call the city on that one.