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California_Cookie
Want to replace exterior natural gas water heater....Questions
California_Cookie

I'm preparing to get the utilities turned on in an older house that's been empty for over 10 years. The aim is to get the place inspected and appraised so I might either buy or (failing that) rent it. To get it adequately inspected or appraised, the utilities have to be on (or so various companies in the area have told me.) The out-of-town owner (who I'm acquainted with and have permission from) ISN'T going to do this part...I am more motivated to live there than he is to sell or rent. BUT it is a fantastic old house that I love.

Step 1 in PROJECT TURNON: Replace outdoor water heater so PG&E is not aghast when they come to turn on gas and electricity. I want to remove the old water heater, repair exterior siding behind heater, hook up donated water heater (a friend was switching to tankless) and build lean-to-like shed enclosure with vented door around it. I'll have a plumber do the actual hooking up, strapping and adjusting of pipes...but want to keep costs down and build the cement base myself.

Does anyone know what the requirements are for this type of cement base in California? (We have many old houses with exterior water heaters in this state, as the temperature is mild and nothing freezes.)

Am inserting photobucket link to pic of this decrepit old heater. (DON'T LAUGH!) Also what I hope to replace it with. (Tried to insert or attach jpegs in post....resulting in extreme confusion, almost despair.)

Thanks in advance....I looked over the last 3 pages of threads and didn't see topic discussed...

dj1
Re: Want to replace exterior natural gas water heater....Questions
dj1

First, remove the old water heater:

1. Shut off the water supply valve and the gas supply valve. I would even replace these two valves.
2. Remove the earthquake straps off the wall.
3. Remove the water heater.

Second, do your siding repairs.

Third, form and pour a pad for the water heater. 3-1/2" or 4" deep concrete will do. Let it cure for a few days.

Fourth, Bring in the new water heater, hook it up (water in, water out, gas. Vent will be connected later through the top of the shed) and strap it.

Fifth, buy a metal shed made for outdoor water heaters (avail at HD or Lowes). This is a 3 side/panel shed (no back panel) - and it attaches to the wall.

Sixth, seal around the side panels and the wall, you can use flex putty made for exterior uses.

Fill the water heater and light it up.

dj1
Re: Want to replace exterior natural gas water heater....Questions
dj1

One more thing, and it goes without even saying: replace gas and water flex connectors.

A. Spruce
Re: Want to replace exterior natural gas water heater....Questions
A. Spruce

Anther issue you may run into are flood zones. If you are in a flood zone, you may be required to elevate the waterheater out of the flood zone area, generally the same height as the house floor will due. Earthquake strapping is a must, regardless of where you are in the state. And, because you're building a shed around the waterheater, it must be quake proof as well, since the waterheater will be secured to it, i.e., attach the shed to the house.

I would recommend checking with your local building department for regulations on exterior waterheater installations.

California_Cookie
Re: Want to replace exterior natural gas water heater....Questions
California_Cookie
dj1 wrote:

Third, form and pour a pad for the water heater. 3-1/2" or 4" deep concrete will do. Let it cure for a few days.

Thank you very much.

Do you know how much bigger one makes the concrete slab/stand, to extend past the base of the exterior water heater in California? I was trying to search the building code on line and wasn't able to locate specifics. I know you'd want to leave some room for air circulation, and also since there's a flame involved (even though it's covered) you'd want to keep it a certain distance from the shed door, etc.

California_Cookie
Re: Want to replace exterior natural gas water heater....Questions
California_Cookie
A. Spruce wrote:

And, because you're building a shed around the waterheater, it must be quake proof as well, since the waterheater will be secured to it, i.e., attach the shed to the house.

Hmmm....I hadn't thought of that. Thanks : )

I was first planning on adapting a design and instructions from Sheds: The Do-It-Yourself Guide for Backyard Builders (2007) by David Stiles. I think it's the first, and easiest, project in there. I can't find a pic, but it basically looks like this, though half the width and with a single door.

But the tin metal cover that's pre-manufactured -- mentioned above -- does sound quicker to just put on (and then secure, of course.) I'll look into those.

dj1
Re: Want to replace exterior natural gas water heater....Questions
dj1
California_Cookie wrote:

Thank you very much.

Do you know how much bigger one makes the concrete slab/stand, to extend past the base of the exterior water heater in California? I was trying to search the building code on line and wasn't able to locate specifics. I know you'd want to leave some room for air circulation, and also since there's a flame involved (even though it's covered) you'd want to keep it a certain distance from the shed door, etc.

Water heater metal sheds are made to fit water heater sizes. A 30"x 30" x 76" would fit a 30 or 40 gal tank, for example. Go to HD and see the sizes. They are inexpensive (less than $140) and easy to assemble.

The concrete pad should be a foot larger, so for a 30x30 shed, form a 42x42 pad. Flood zone is a consideration I overlooked. Make sure the water heater is not in risk of flooding. Also keep vegetation off around the shed.

I have 3 homes with water heater sheds, and the way they're built, they allow enough air for proper combustion. Being outdoor, spiders take over and invade them...rent free. In the old days, water heaters had unsealed burner compartments, and spiders would interfere with gas flow, but today, the thing is sealed. However, make sure that the combustion vents are clear at all time.

California_Cookie
Re: Want to replace exterior natural gas water heater....Questions
California_Cookie

Thanks for pad dimension info. It's not in flood zone to my knowledge, but will ask a local builder I know, just to be sure.

dj1 wrote:

Being outdoor, spiders take over and invade them...rent free.

We have so many black widow spiders here! They nest all over the place, outside. I was freaked out until I read up on them, and they're reportedly timid, and don't go seeking out people. They'd much rather hide.

So at least if I make a lot of noise and knock things around before handling them....the odds seem in our favor.

dj1
Re: Want to replace exterior natural gas water heater....Questions
dj1

Usually when I have to replace a water heater in a shed, I spray half a can of raid, close the door and wait a few minutes.

Then use a broom to kind of sweep the cobwebs away. Remove the water heater out, and clean the inside thoroughly, before I can continue. I just did one two weeks ago.

Back to the slab, here's a tip: set the forms with a tiny incline away from the structure, but not too steep, so all water (leak or rain) will drain away from the house.

California_Cookie
Re: Want to replace exterior natural gas water heater....Questions
California_Cookie
dj1 wrote:

Back to the slab, here's a tip: set the forms with a tiny incline away from the structure, but not too steep, so all water (leak or rain) will drain away from the house.

Yes! Hadn't thought of that. Will groom it very very slightly for runoff.

Jack
Re: Want to replace exterior natural gas water heater....Questions
Jack

Before you get in too deep check with your local building department, many jurisdictions require systems be brought up to code if they have been disconnected for a given period of time. Bringing an old house up to current electric code requirements for GFCI and AFCI can be very expensive.

Jack

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