Minimum Slope for Heater Vent

[weaver]

I'd like to develop some additional height for water heater replacement. What is the minimum slope for the horizontal run of a vent? Have 23" from ell out of heater to tee with 6" vent from furnace right by the entry into lined brick chimney. Could we go as far as 1/4" in each 12"?

I'd like to get some idea of brand and model options before plumber comes on site.

Many Thanks.

Bob

[Doherty Plumbing]

Well I don't know about Ohio but to my knowledge as a gas fitter in BC there is no "minimum" but you need to have some slope. 1/4" is plenty.

The only real thing you need to worry about is the length of the horizontal run. The lateral length of the vent connector will directly effect what size the vent shall be.

If you are just running a HWT (Lets call it 40,000 BTU) you can have a lateral of 10 feet or so with an overall vent height of 15 feet.

I hope this helps.

[weaver]

It does help. I would be getting a 40,000BTU. Several of the new HWTs are bigger than similar models from years ago... Thanks for reply.

[Doherty Plumbing]

No problem. Good luck with the project.