# Water heater flue pipe size and type



## user8031 (Dec 14, 2011)

I'm interested if your State and/or municipality requires you to use double wall flue pipe when you run a certain distance away from the heater? We can only use double wall unless we are withing 6 foot of the liner or plenum. From there we can use 26 Gauge. Also, we are no longer allowed to use any 3" flue pipe either. Gotta be at least 4". 

What does your code require?


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## Catlin987987 (Nov 12, 2010)

wyefortyfive said:


> I'm interested if your State and/or municipality requires you to use double wall flue pipe when you run a certain distance away from the heater? We can only use double wall unless we are withing 6 foot of the liner or plenum. From there we can use 26 Gauge. Also, we are no longer allowed to use any 3" flue pipe either. Gotta be at least 4".
> 
> What does your code require?


Same here but we can use 28 gauge for a water heater


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## Greenguy (Jan 22, 2011)

Out here they use alot of 3" especially on the mobile homes, buy they have of course follow a different code from regular single family residences. the rules are a mix of 2003 UPC and 2006 also depending on what kinda of mood the city inspector is in.


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## BROOKLYN\PLUMB (May 21, 2010)

We need to go to double wall when going through a wall (even non flammable) or outside (b vent) needs double wall stainless


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## ken53 (Mar 1, 2011)

Here we have to use 4" over 30000 BTU if it's co-vented like with the furnace otherwise 3" is good but the inspectors want us to use 4" on everything so they don't have to think.


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## ditchdigger (Aug 12, 2012)

We are required to use double wall on all water heater vent pipe


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