Condensing Roof Termination 20"" (above roof)

I have owned a Rinnai water heater for almost seven years. I installed it myself and did a fair job if I say so myself but there was always a problem with it where the water would heat up alright for about 3 or 4 minutes but then would cut off by itself. You’d have to turn off the water and start it again right away for another 3-4 minutes of hot water. I tried everything to fix the problem but nothing really worked. I even had tankless water heater repairmen out with no help. Some thought it was the size of the gas meter so I have that updated and increased in capacity, nothing. Some thought it was the ½” gas pipe that came off the wall, so I changed it to 1”, nothing. I researched the problem on the internet and found a little blog about the flu size and type. After all this time and money spent on trying to fix the problem it turned out to be the flu type all the time. After replacing the flu to this type (pvc double walled with seals) the heater now works flawlessly and I noticed that where the fan used to wind up a lot when it was being used but now the fan just stays at a steady pace. I hope this little insight I came across helps others that might be having the same issues.

I originally wanted to route the concentric vent horizontally through the brick, but after reconsideration, I chose to use the existing hole in the ceiling from the tank water heater. This vent, along with 2 -45’s and an extension made the job easy. I do wish that the gasket lubricant did not evaporate so quickly however.

Cap off your new tankless heater with a concentric vent that tells the neighborhood - f you and your white trash roof vents, this puppy is made for a high efficiency water heater.To match the existing shingles I'd suggest hitting it with some primer and paint to match, it is plastic to use appropriate bonding primer.

Scant instructions included in the box with this fancy plastic pipe within a pipe. But my contractor was able to figure it out. As a bonus he also didn't fall off the roof installing it!

As described but the do make a 19" one. I didn't know at the time.

Great quality product. Over priced for what it is.

Working well so far, just be sure to keep the lube that comes with this product as it's very difficult to secure the other pieces without it!

so far so good....