Furnace exhaust

[LeRoy D. Holm]

I am working with a HUD program and the plumber says he cannot install a T or 90 degree on the exhaust coming out the roof. I used to work for a plumber and we installed 2 45 degrees to long sweep the 90 degrees.

I just want to know why it is not legal as the plumber was very rude about not installing it. If there is rule about it fine, if not he will be dropped from the HUD contractors we use.

I cannot find any rheem manulas online so I may have to go to a HVAC compnay and ask

[Robert J. OConnor]

I think the plumber is right.

You can contact Rheem with the model/serial numbers of the furnace if there really is a concern. But most higher efficiency furnace manufacturers (including Rheem) specifically do not want an elbow or tee on the exhaust (that is only installed on the intake).

See Pg 25 of this Rheem RGFD series installation manual for an example of what I am talking about ... www.allreds.net/WS2/docs/rhe/rgfd_manual.pdf

[mstankiewicz]

Great reference Robert, Wish I would have had it a week ago when I took a Commercial Building Code Inspector Exam.

Actual question dealt with that, along with the height from roof. The height answers we normally associate 3 feet, 2 feet, and 10 feet from etc. The answers were 2 feet above and 2 feet from, 3 feet above and 3 feet from, 18 inches and 3 feet from.

There is more information as well in the International Mechanical Code (IMC) and International Existing Building Code (IEBC).

Just another reason we have all the license and training requirements.

[Joseph Hagarty, CMI]

If permitted...
It is the first time I have ever seen PVC vent run the B Vent.
How are the pipes sealed exiting the metal vent?

Is this common in your area?

[LeRoy D. Holm]

The pipes were caulked, you see this once in awhile.

This home had no basement and is single a level and the plumber was crying that he could not get it to the exterior walls with hanging it from the ceiling exposed. The home owner of course did not want that, so he decided to reuse the chimney with the pvc.

[Joseph Hagarty, CMI]

The PVC could have been routed thru the roof and properly flashed (at an additional expense).
Routing thru the existing B Vent may have been what the Homeowner wanted
but
that does not make it an approved installation