Furnace Vent

abfhand

Hello. Just had a Carrier Infinity Furnace put in [scrach and dent]. the 2'' vent going to the outside sounds like gurgling water when running. The pvc is most level and doesn't have enough of a drop. Will this in anyway harm the furnace? thanks..

mgv79

yeah if you here water gurgling that is not a good thing, if it is almost level, then that is not good enough you need rough 1/4" per 3 feet slope is the general rule of thumb so you might want to take a look at having that fixed

hvac122

As said you need slope so the condensation drains back to the furnace and out the condensate. Not sure about Carrier but most manufactures say 1/4" per foot. If this is not done then you may get intermitent failures.

bigMikeB

1/4" per foot as the man said.

abfhand

Thanks for the inputs. We couldn't place a concentric kit out there because of the way the joists are running. Had to do a back 'S' using 45's to go above the poured basement wall. It is probably a 30' run from the furnace to the outside. Strange thing is, from the outside back - the pipe is probably an inch and a half lower on the furnace side and 4' from furnace is showing mostly level. Really don't know how fix that now.. Thanks again. Will

bigMikeB

Couplings.

redline

How many bends are in the run?

abfhand

3 not counting the outside 90 & 45.

The only way I'm gonna get it right is to cut the pipe where it goes into the furnace side joist and make that hole deeper so the pipe will be lower and shorten the pipes to the furnace. It mostly gurgles for a few seconds on the pipe outside then smooths out. Plenty of steam from the exhaust showing it's getting thru okay but still hear the girgling.
It's a Carrier gas furnace Infinity 80,000 96