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.

Thanks,

David

On Mar 29, 12:24 pm, David Mathog wrote:
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.

Thanks,

David

An active online source of good advice and parts for HVAC is
Arnoldservice.com. They could have the rght gasket or material you
need. Failing that, there are the industrial suppliers, Grainger and
McMaster-Carr. You might find some sheet material for exhaust gaskets
at auto parts store, but IMO the others are more likely. Good luck.

Joe

On Mar 29, 12:24 pm, David Mathog wrote:
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.


How hot is it actually? I'd think a standard gasket material would
suffice, but if not sure, head gasket material certainly will. OTOH,
I'd probably go w/ the RTV solution.


A question, though...can you not pull the bearing(s) from the motor
and simply replace them rather than toss the whole motor?

goop $3

hi temp auto gasket $4


On Thu, 29 Mar 2007 10:24:15 -0700, David Mathog
wrote:

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.

Thanks,

David

dpb wrote:


How hot is it actually?

Not sure, but probably pretty hot as it is attached to the exhaust path
(I think.)

head gasket material certainly will

Yeah, I figured head gasket material could take the heat. However I
wasn't so sure that it wouldn't release toxic fumes.

A question, though...can you not pull the bearing(s) from the motor
and simply replace them rather than toss the whole motor?

Mostly because I don't know how to replace bearings, where to get
replacement bearings, and especially, any way of knowing how well the
replacement bearings would stand up to the heat.

Thanks,

David

On Mar 29, 1:50 pm, David Mathog wrote:
dpb wrote:

How hot is it actually?

Not sure, but probably pretty hot as it is attached to the exhaust path
(I think.)

head gasket material certainly will

Yeah, I figured head gasket material could take the heat. However I
wasn't so sure that it wouldn't release toxic fumes.

Don't think there's any significant chance of there being anything of
any concentration to be of any concern...what, in particular makes
this such an issue in your mind?

A question, though...can you not pull the bearing(s) from the motor
and simply replace them rather than toss the whole motor?

Mostly because I don't know how to replace bearings, where to get
replacement bearings, and especially, any way of knowing how well the
replacement bearings would stand up to the heat.

Replace bearings by pulling or driving old ones out and reversing the
process. This, of course assumes the motor is such that one can get
access to do so.

As for where to get them, there are bearing distributors in any town
of even moderate size -- if you can get the old ones out, they can
match them. If there is anything special about them (and I kinda'
doubt there is), that will be encoded in the manufacturer's part
number and they'll match that, too...

How big a motor is it? There's a motor service outfit here that will
repair virtually anything that isn't welded closed for normally quite
a bit less than a replacement. If you don't feel up to the task
yourself, there's another alternative. Granted, if it's just a
"throwaway" design, not feasible or cost-effective, but I'd surely
look into it before I just tossed the old one if it seems to be
running fine except for the bearing(s)...

Just imo, fwiw, ymmv, $0.02, etc., etc., etc., ...

dpb wrote:
Don't think there's any significant chance of there being anything of
any concentration to be of any concern...what, in particular makes
this such an issue in your mind?

Mostly an abundance of caution. Also having a pet bird in the house, as
they are much more sensitive than people to such things. The fumes
from an overheated teflon frying pan can kill a bird on the other side
of the house, but it won't do anything to a person.

How big a motor is it? There's a motor service outfit here that will
repair virtually anything that isn't welded closed for normally quite
a bit less than a replacement.

Good point. I called one of the local electric motor repair shops and
he said that since the replacement was only $70 it wasn't worth
repairing this motor. Something to keep in mind though if the main
blower motor ever goes.

Thanks,

David

The bearings are cheap but a bitch to get to. You have to not only disassemble the ECM motor but you have to unsolder the control from the motor. It can be done but I would not recommend it for the amateur homeowner. On the other hand, unless it's cold outside and you need heat, what do you have to lose by trying to replace it? Worst case is you buy a used one on ebay but that could take many days to arrive.

Here are some videos I've created on this very subject:

https://youtu.be/QOpQyHoOhBE

https://youtu.be/TPCAgHj_0kU