Polypropylene pipe question

JDPT

Hello,
We are installing a dunkirk 125 wall mounted condensing Boiler. My contractor plans to use 3 inch polypropylene pipe for the vent and pvc for the air intake. After I read the manual it says that if you use polypropylene pipe to vent, the air intake must also be polypropylene. My contractor does not feel that is necessary ( and has never come across that in his 30 years and cannot imagine why). When I asked a tech from Dunkirk I could not get a actual reason why. I realize it is more expensive to use the polypropylene for the intake and wondered if anyone has an explanation. And yes, I know the rule is if they say it then do it, just curious.....thank you.

Jellis

I googled the dunkirk manual to read for myself and found the following

"Vent Material Options:
1. 100mm / 60mm Polypropylene concentric ("4 inch/ 2 inch")
2. 80 mm polypropylene twin pipe (MUST be polypropylene on BOTH intake and exhaust) ("3 inch")
3. 3" Twin pipe CPVC (PVC optional on intake ONLY)."

you could use the cpvc vent and PVC intake as recommended in option 3
Im not sure why they recommend poly for intake as well in option 2... maybe because the twin pipe adapter is made only for metric poly pipe?

Zman

JDPT said:

Hello,
We are installing a dunkirk 125 wall mounted condensing Boiler. My contractor plans to use 3 inch polypropylene pipe for the vent and pvc for the air intake. After I read the manual it says that if you use polypropylene pipe to vent, the air intake must also be polypropylene. My contractor does not feel that is necessary ( and has never come across that in his 30 years and cannot imagine why). When I asked a tech from Dunkirk I could not get a actual reason why. I realize it is more expensive to use the polypropylene for the intake and wondered if anyone has an explanation. And yes, I know the rule is if they say it then do it, just curious.....thank you.

This is a great question. I have no idea why you can't use PVC for CA

lchmb

Sorry to say, with it listed like that I would spend the extra money to have it done. If you have issues they may have warranty issues if you dont follow the spec's...

EBEBRATT-Ed

@JDPT

Any make boiler that is installed you must follow the boiler mfg. instructions. That being said there is no reason PVC can't be used for an air intake.

But if the manual says poly that's what you must use

pecmsg

Who purchased and is installing this equip?

JDPT

My contractor is of course using the poly for the intake as the mfg. instructions. I was just wondering why it is that way. Again, just curious.....