"Jim" wrote in message
om...
Our propane water heater vents through a 3" PVC pipe on top of the
unit.
It look as though a bead of silicone(???) was placed around the area
where the PVC piping connects to the vent line from the heater itself
(it was installed about 6 years ago).
I have noticed that this seal has sprung a very small leak and when
venting, some of the air is blowing into the surrounding area.
Obviously, I would like to reseal this connection.

Is a special purpose silicone used for this seal?
The instruction manual says to use a high-temperature silicone for the
seal, but no local stores seem to have heard about this type of
silicone.

Go to the auto parts store and get a tube of high temp silicone gasket maker.
May be blue in color but works fine. You can pay more and get duct joint
silicone at a plumbing supply company.

Tom J