I have a PVC furnace exhaust pipe in my attic that is running horizontally for a short bit to get from the service chase to where it penetrates the roof. It is currently dripping water onto the ceiling right by the 90' fitting where it turns to go down the service chase.
I have a few questions that I hope the experts here can help me with.
1> should the PVC be glued with regular PVC primer and glue like is normal for sewer drain/vent? (It looks like the installer used black ABS glue)
2> Should the exhaust vent be installed such that it always has a slope down towards the furnace? (ie. any "horizontal" runs should have a slight slope towards furnace?)
3> Should the air intake vent also be sloped toward the furnace? (It's next to the exhaust in the chase and come together for a concentric vent penetrating the roof)
4> I would guess water (rain) will sometimes get into the exhaust and air intake vents. Is there anything I should be concerned about with that? Is that rain water going to normally wind up win the same place as the furnace's condensate?
5> what else should I be looking for? Obviously some things were not done right by the installers, so now I wonder what else I should check on.