Power assited fan for flue

[RobertSmith]

I've never run across this before. There is a power assisted fan for flue because the flue does not have a proper upward slope either in the furnace/water heater closet or in the attic.

Is this setup allowed? Issues to look for?

thanks,

Rob

[Bob Harper]

Lack of clearance to combustibles
Positive vent pressure in unlisted connector and vent

[RobertSmith]

Thanks, Bob,

How can you tell the vent and connector is unlisted?

Also, just noticed, what about the 1ft rise before making a turn. Does the power motor null-n-void that code?

Rob

[Bob Harper]

That B-vent is listed only for CAT I negative vent pressure so it is unlisted for positive pressure.
No, the fan does not change the code or listing.
Note zero clearance to insulation, which is wrong.
Note the adapter for splicing brands and types of pipe, which is not a listed component in most systems. It would also need to be screwed to the B-vent at the slip joint, which would void the listing.

Looks like lack of proper support.
HTH,