DiversiTech CVENT-3 3-Inch Concentric Kit for Tankless Gas Water Heater, High Efficiency Furnaces, 7.75" x 40" x 6.75", White

I used this on my AO Smith tankless hot water heater. Great quality, good price. One tip - the instructions tell you do bore a 5" hole through the home, but I went with 4.5" instead and, while it's a very tight fit, it's a much cleaner install than having to fill 1/2" gap around the pipe and your exterior sheathing.

Simple and complete install

Instead of drilling two 3" holes, one for air intake, and the other for exhaust, this kit only use one 4 1/2" hole for both duct work. You just need to run two 3" PVC pipe (one from in-take port and one from exhaust port) from the water heater to this kit.

I ordered the 3 by accident, found out later I have two inch pipes. Amazon took it back and gave me credit. The CVENT-2 from this same seller worked perfectly in the hole of the one I replaced. With no prior experience I was able to replace the PVC venting from my furnace to this concentric kit. The repair man wanted more than $1,000 to do the same job, citing this vent as the most expensive part! I'm thankful for this seller and Amazon for saving my family a bill we couldn't afford.

This is the same, very high quality vent one would find in an HVAC supply house. I have installed several of these on both high efficiency furnaces and on tankless water heaters with no problems. The fit and finish on these is perfect, they are well packaged, and about $30.00 less than buying them at a supply house. I was well pleased. If you are undertaking a new furnace or water heater project, and need to use PVC to vent and supply combustion air, these work well for horizontal or vertical installations.

The "buy used" one i received had one broken fin, during the install the top of torpedo fell on the porch and the second fin broke resulting in uneven hold on the outer pipe, looked crooked and un-sturdy.The second used one i received was perfect.The center pipe is the exhaust vent connected by 3" sch 80 PVC and air intake is the outer pipe connected by flexible 25' duct pipe. The flex pipe for air intake was a good idea due to limited space so it allowed some flexibility in the installation.

This item worked great with my combination boiler. It was substantially less than vents offered at local HVAC and home improvement stores. Fit like a glove but I needed to order https://amzn.to/2Sb6ugw Trim 4" PVC trim rings to make a clean installation through the exterior wall.

I didn't want two holes in my roof for the new furnace installation (went to high efficiency) and this is the perfect answer.