Flue Venting clearance

[Lanny Freng]

Found this in the closet, flue runs up from basement through 1st floor then to attic/roof. Water heater is only appliance running in it. Warm to the touch but not hot when operating. 1-2" of clearance from combustibles is what I was thinking. Be better with an enclosed chase around it. Not sure if double or triple walled. Couldnt tell, no markings on the venting. What say you?

[H.G. Watson, Sr.]

It must be enclosed when passing through an occupied floor - behind closet door doesn't count as being separated and enclosed.

B-vent would be the norm, requires system componants including support at floor/ceiling assemblies, attic penetration & roof. Blocked, stopped & supported. B-vent requires an AIR SPACE around same which requires cleance to all including combustibles. Failure to do so causes "hot spots" and deterioration as well as interferes with draft. HOLES in flue within CO hazard.

Note the rust where shelf makes contact. Note wood closet pole to same as well.

Vast majority of time when water heater is orphaned requires resizing the vent. This needs to be addressed PDQ - and vent likely requires replacing anyway, when it is, it should be sized appropriately and installed according to safety code(s) and the manufacturer's instructions, and according to its listing.

[Lanny Freng]

Good Info thanks HG!