Hi again, guys. Been a while.

So my elderly neighbor (He's got to be in his late 80s) comes over a few minutes ago to ask if I could look at, and possibly help him replace, his gas water heater. I get to his thin wood water heater shed (which is about a foot under his patio roof) and to my shock I see that he has had no heater vent on this old leaking 30 gallon 1998 model heater. The top is laden with water and rust with just a vent connector and nothing more. The two pipe nipples have had their galvanized coating burned off it appears also.

Okay, so what kind of vent pipe do I need, but more importantly, does the angle of the pipe matter as far as drawing heat out goes? The heater shed is located on the corner of the house, so I can simply go straight up, or come off right from the first shed opening at an angle and simply go to the side of the structure. How big do the holes have to be if I end up going through two roofs? In California if that matters.
As always, thanks.

Sizing depends on the “top hat” vent connection 50 gallon and under are usually 3” smoke pipe above 50 gallon is typically 4” smoke pipe be sere to install a termination cap in the roof to prevent water from entering the smoke pipe and dripping into the water heater

>In California if that matters.

Two straps are required state-wide. Plumbers tape/perforated iron strap is no longer approved for heaters 40 gallons or greater. Just buy the two-strap kit at any local store, Large or Small based on your water heater capacity. If you just buy the large one for a small heater, you have to cut some holes in the steel strap yourself.


Clear water heater installation guide published by City of Santa Cruz:
[www.cityofsantacruz.com]

Simple strapping diagram as published by San Diego County:
[www.sandiegocounty.gov]

Less simple strapping diagram as published by Los Angeles City:
[www.ladbs.org]

Complete code including strapping and venting:
California Plumbing Code Section 507.2


After the 1989 Loma Prieta quake I had to clean up a smashed heater that had been apparently well-secured by a single strap. The codes make sense. Home Depot sold out of water heaters within an hour. They were taking payments manually, as power was out through most of the Bay Area.

I can go straight up with this vent pipe in this situation. Is that a good idea or should I come off the top of the heater with an angle? In other words can going straight up like that provide too much of a draw of heat, not to mention rain possibly coming down straight through?



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Straps I'm not worried about as it looks to be beautifully strapped in. I've got a plug-n-play situation here.

My question was more on the venting. He's had none all this time. So I go with single wall vent pipe exiting the water heater, and then join it to a double wall pipe leaving the roof?

It's the vent pipes I have questions about.



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yeah, 3 inch single wall leaving the heater and transition to double wall pipe.. use a 3 foot piece starting at 12 inches below the roofand extending 2 feet above the roof. use a good quality roof flange that has a circular spacer at the bottom to protect the wood around the pipe.
rain won't come in if you use a roof cap.