Water heater replacement

[Bill]

I will soon be taking posession of a 1994 Dutch doublewide on a foundation on private property. The current water heater works, but is electric, and I want to replace it with a natural gas model that would be powervented with PVC pipe thru the outside wall. A guy at Home Depot told me I'd need to stick with a water heater that's specifically built for manufactured homes. What's the difference? Is there really any compelling reason I would want to or need to stay with a unit that's specifically built for use in a manufactured home? The powervented unit would be substantially easier to install, since it only requires a 3" PVC pipe out the side wall as opposed to installing another roof vent. The electric unit sits next to the furnace, up against an outside wall.

[Tom]

Stick with electric. The venting your describing is not up to code. MH gas heaters have specific venting requirements. Your local code enforcement would not allow you to install as you described. Tom

[Bill]

Tom, can you be more specific on why it wouldn't be up to code? Sticking with electric is out of the question. Way too expensive to operate considering I have natural gas available.

[Tom]

MH gas heaters draw gasses away differently. The design is totally different. Im not sure its easily described, but if you physically looked at them you could see the difference readily. The other consideration is the vent itself is shielded differently due to the fact of the wall thickness being different between a stick built and MH's. I can only give you advice according to how the code enforcement would view your installation. If you would like to get into a variation of what code would be, then you probably should contact a local MH repairman and your local county code section to see if what your describing is legal. Most counties do require a permit to install a gas WH, obviously for safety reasons.

[Bill]

Thanks much for the info Tom, I will most definately check with the township before I do anything. The type of water heater I have in mind is vented with standard PVC pipe thru the wall, and heat from the vent pipe is not an issue. Not sure how they accomplish this, but I've had 2 of them in previous houses, and they worked great. This type of water heater is a high-efficiency model.

[Tracy]

Bill,
A Manufacture Water Heater draws air from under the home. This is because of the small area where the unit is placed not having enough air. You will also have to vent the heat pipe throgh the roof. Everything you ask is do-able if your heart is set on a gas W/H. Be prepared, you will need a hole in the ceiling and roof, a hole in the floor and a gas line run to the unit. The PVC pipe you speak of will work for the plumbing and the Pressure realease valve just fine.

FYI--- A good idea is to run the pressure realease valve to the outside of the home.

Good Luck

Tracy

[Tom]

FWIW, if by any chance you should be inspected by either the gas company or a code inspector, their versions of what code is or is not is sometimes not in line with how we interpet it. A sure way to get into to trouble is to not check ahead of time. I have seen the gas shut off to homes until repairs were made to job a homeowner thought was code. Tom

[Greg]

Another main difference is that "not for installation in mobile homes" water heaters do not come with the alternate jets for the use of natural gas. Hook up one of these to propane and it will blow up.
Check with local building officials.
In California pvc is not approved for water connections other than sprinklers and hose bibs. cpvc is approved for hot water usage. Here, there is a tag available for $25.00 which states ( in color and lettering approved by HCD ) "For use with natural gas only". Which gets you around the wording "Not for use in a mobile home", However states are different.
Be sure to check.
Greg