wrote in message

Is it OK to have the radon pipe running next to the water heater
flue? I checked with the city, but they claim the code only says to
"install per manufacturer's instructions." Elsewhere I have heard
there should be 2" of clearance between the flue and anything
flammable. Is the PVC pipe considered flammable?

Thanks in advance!

Dave

PVC for use in building must have some fire retarding properties. That does
not mean it cannot burn with another source of igniton. I doubt it is
going to burn the house down, but get some clearance between them. Contact
can eventually meld the PVC if it gets hot enough. Just a wedge to get an
inch or so should do the trick.