Power vented water heater

[jeepit]

I am about to have a water heater installed and the venting goes thru a 4 foot thick field stone wall, so changes there is not an option. Currently a metal 3. 5 inch pipe runs thru the wall to carry exhaust outdoors. My plumber was over and looked at the pipe and says it is too small. Being power vented I would think it would not make a difference. The current powered vent has been in use for over 15 years. Can the new power venting safely be reduced to 3. 5 inch metal piping? Not sure what standard exhaust power venting diameter is... .

 

[p-Bar]

Call the manufacterer of the heater and ask them

 

[Larry Willard]

All the power vent heaters I have seen require schedule 40 PVC pipe to vent them. The gas code requires you to follow the manufacturers installation instructions. Depending on the BTU input and the total length of the flue, if you can get it closer to where it exits, a smaller pipe may be acceptable. You should check with different manufacturers, since each one will be different. I have seen them with vents from 2" through 4",

Larry

 

[jeepit]

Thanks Larry, I have been on a few sites and they do say a reducer can be used for my situation. For what its worth, the run to the existing pipe is only about 5 feet.