I've got a Rheem high efficiency furnace which has a leak. Itís where the pipe transitions from what looks like (black) ABS pipe which comes from inside the furnace to the PVC pipe which takes it out the roof. My guess is that with the different materials used the glue failed. I canít cut out the problem area because its right at the furnace, I will need to replace the pipe that goes into the furnace. Is it safe to replace that pipe with PVC or does this section of pipe need to be a high temp plastic pipe? If does need to be something different than PVC what should the transition look like?
The furnace has the vent entering at the top which is where the main blower is located. This is the section of pipe that would need to be replaced. The burners are at the bottom and sectioned off from the top.