Single wall furnace flue

On a modern (1994) Goodman furnace, is a single wall flue ok?

In my area the basic answer is no to single wall must be double wall where it pentrates ceiling and or roof must be double wall in any attic space.

Thanks, Charley. This is an unfinished basement, connected to the original masonry chimney chase.

Sounds fine to me.

I should add that you would need a chimney liner.

Thanks Jason1.

Single wall would be fine in that example we were not on the same page:)

Early 90’s flues used by Goodman furnances is suspect to me. Was it Ultra-Vent? (grey plastic).

If yes, inform the client their furnace flue might be under immediate recall.


By the sounds of his description, and it venting to the masonry chimney, I would assume it is a mid efficient unit utilizing a single wall metal flue.

This is from the CPSC link:

**For furnaces, only HTPV systems that have vent pipes that go through the sidewalls of structures (horizontal systems) are subject to this program. **

Good links though :slight_smile: