ABS to B-vent connection

yolhovsky · June 13, 2009, 2:43am

I never seen ABS vent pipe from induced draft water heater connected to B-vent. Any comments or concerns?

DHW connection.jpg

belliott · June 13, 2009, 2:59am

I had no idea ABS was even allowed.
Was there a glue or was it taped together.?
I cant quite tell.

yolhovsky · June 13, 2009, 3:38am

ABS was allowed until August 1, 2007. After that day they have to use CPVC. This ABS vent pipe was glued to the B-vent. Since this is a bungalow, I don’t really see a big issue with backdrafting due to the presence of induced draft fan. On the other hand, this is definitely not a common practice.

belliott · June 13, 2009, 4:18am

Hmmm
I did not see much on look up but they are 2 dissimilar materials with different expansion rates.
May need a special transition .