HVAC Site - Professional HVAC Contractors Forum banner

How to Connect 80% Furnace Inducer Motor to B-Vent

182 Views 2 Replies 2 Participants Last post by  mnocket
I'm trying to replace my inducer motor, but I can't figure out how it's supposed to connect to the double wall B-vent duct. The motor flange does not fit into the B-vent duct. The original installers addressed this issue by crimping the flange, but since it's cast aluminum rather than sheet metal it really didn't crimp much and as you can see from the screw holes in the picture below it barely managed to engage the duct.

Cylinder Nickel Gas Auto part Household hardware

I'm guessing this is not the prefered way to try to make the connection - I also don't own a crimping tool and doubt I have the strength to get a decent crimp. Here's a picture of the replacement inducer motor.
Camera accessory Scientific instrument Gas Camera lens Cameras & optics

You can see it's cast aluminum not sheet metal. I'm sure it's intended to be a slip connection.

The inducer motor connects directly to a 90 degree elbow. Do to space limitations outside the furnace there is no room for anything other than connecting directly to the elbow.

For completeness, here's a picture of the elbow showing where the inducer motor needs to connect.
Automotive lighting Hood Automotive tire Motor vehicle Automotive exhaust

The inducer motor comes very close to being able to slide inside of the inner elbow duct, but doesn't no matter how hard I try to make it fit.

Given the tight space concerns, I don't have any room for any adapter that will add more than about 2" the length.

Any ideas how to make this connection? Is this inducer motor intended to fit a single wall vent pipe? If so, can I use a single wall 90 degree elbow and connect it to the rest of the existing B-vent? If so, how?

Ann insights are appreciated as I'm stumped as to how to move forward. Thanks.
See less See more
1 - 2 of 3 Posts
There is a couple from single wall
To b vent but you said there is no room so probably have to do what they did. Crimping
Thanks for the reply. I wound up using a single wall elbow and then the coupling on the vertical run where I had room.
  • Like
Reactions: 1
1 - 2 of 3 Posts