A bearing on the draft inducer motor on our Carrier 58PAV furnace is
starting to go. In order to be sure that was the problem, and to get to
an angle where I could read the markings on the motor, I unscrewed the
draft inducer and pulled it out of the furnace. Sure enough there was
audible bearing noise even when the motor was turned by hand. I'm
shopping now for a replacement motor, which are available from several
places, and which looks like it will cost around $100. Much cheaper
than the estimated repair price from the folks who sold us the furnace
10 years ago - they thought it would be about $1000, and insisted that
the entire inducer assembly needed to be replaced.
Anyway, back to the subject at hand, between the inducer hardware and
the furnace there was a 6" diameter gasket, about 1/2" wide and quite
thin (1/16" maybe?), which pretty much fell apart when the inducer came
out. It probably didn't help that the three mounting screws went
through that gasket. The gasket was made of fiberglass and something
that looks a lot like paper, but may not have been. The carrier service
manual suggests resealing with high temperature RTV sealant, like GE
162, 6702, or Dow Corning 738. I'm not a big fan of glop gaskets, they
tend to either make a mess or glue the part on more or less permanently
(even though they aren't supposed to). On the web I've seen suggestions
to use folded aluminum foil, but that doesn't seem like a good long term
solution since it will put dissimilar metals in contact and electrolytic
corrosion would eventually likely result.
What else could I use to make a high temperature gasket for this
application? Preferably something that can be found locally
or easily ordered off the web. Would one of the gasket materials used
in cars, and so available at the local car parts shop, be appropriate?
It's kind of important that whatever is used not out gas noxious fumes
when it's heated up.