Correct gauge flue pipe

pwarfield

Hello, can someone tell me the correct gauge flue pipe (6 inch) for oil fired residential boiler in Massachusetts currently 26 gauge is being used . My son was told by chimney contractor that 24 gauge is required. I’ve been away from the trade for quite some time and don’t remember. Boiler is less than 4ft from chimney.
Thanks

STEVEusaPA

24ga. for 6". Unless the manufacturer says 26ga. But usually in their instructions they defer to local/national AHJ.

That being said, 24ga is rarely stocked in my area (Philly suburbs), and rarely used. In 30 years I've never seen any 24ga. on any equipment with a 6" flue pipe.

retiredguy

@STEVEusaPA, you need to move to the other side of the state where 24GA flue pipe is in abundance.

EdTheHeaterMan

The pros have all seen 30 gauge duct pipe use as Vent Connector. This is wrong, mostly because it will fail (rust thru) much sooner than 26 or 24 gauge, and definitely, because it is not up to code.

STEVEusaPA

retiredguy said:

@STEVEusaPA, you need to move to the other side of the state where 24GA flue pipe is in abundance.

Yeah but the commute would kill me.
They only seem to have black stove pipe, fixed elbows, never a wye, reducer or cap. I think @Bob Harper gave me a source near me years ago...but I forget...lol

EBEBRATT-Ed

I agree with @STEVEusaPA

I think the codes call for 24 gauge but same here the supply houses usually only have 26 gauge