Need help installing a 4" gas vent

[Marchok]

Anyone know where I can get either a 90 4" vent so i can go out the side or a 4" vent that I can go through the roof of my airstream.
I am installing a wall hung tankless water heater in a closet and I dont know where to start with the vent.

[cameront120]

Any supplier of plumbing/mechanical supplies will have them. I suspect you'll need a B-vent (they usually have a 4" inside diameter and 6 or 7" outside diameter.

[Marchok]

Thanks. I'm stuck on how thick the wall/ceiling is and whether to use a vent similar to the fridge vent or more like the vent used on the furnace

[purman]

Originally Posted by Marchok

Thanks. I'm stuck on how thick the wall/ceiling is and whether to use a vent similar to the fridge vent or more like the vent used on the furnace

Most AS walls are 1 1/2 inches thick. At least my 1968 is. Fridge vent might be a little over kill. Look at some of the vents on vintage trailer supplies web sight and see if the will work.

[jm2]

gas fired wall hung instant water heaters generally use a coaxial vent arrangement that often projects more than a few inches from their mounting wall.

check with your heater manufacturer for their specification.

if the water heater is built & certified for RV use, the manufacturer will have the right parts available through their normal distribution channels.

if it's not built & certified for RV use, you might want to rethink what you're using.

ymmv.