PVC exhaust

[Lanny Freng]

Got about an 8 yr old furnace with a PVC intake/exhaust. It looks like when they installed it the exhaust PVC didnt line up perfect so they instead of redoing it fitted with a rubber splice boot with the metal wrap around it. Basically two screws holding it on. I dont like it. Chance that it could get bumbed or come off over time. Obviously neither would be a good situation. Anyone know if this is allowed? I would think a solvent welded connection would be mandatory from the furnace to the exterior.

[Markus Keller]

Can't really imagine that it is allowed. Never seen any install manuals that discussed it. Due to the acidic nature of the exhaust product erosion of the rubber over time would be likely.
Never seen such an install either.

[David Bell]

As long as the connector does not inhibit the condensation flow back to the unit, it should not pose a problem. Many manufacturers have a boot that is used at the connection to the vent fan, they have a drainage port built into them but, also serve as a vibration isolator.