Mobile Home Water Heaters

[Mike Birenbaum]

With just about every mobile home I inspect, when I get to the water heater the mfg. label states (something like) "this appliance is not certified for use in a mobile home". What differences are there between a gas fired water heater for a standard SFR and a mobile home? Is there a safety concern? If so; I'm looking for specific clarification....Any help is always greatly appreciated.

[Gunnar Alquist]

With just about every mobile home I inspect, when I get to the water heater the mfg. label states (something like) "this appliance is not certified for use in a mobile home". What differences are there between a gas fired water heater for a standard SFR and a mobile home? Is there a safety concern? If so; I'm looking for specific clarification....Any help is always greatly appreciated.

Mike,

Same here.

I have contacted tech support at two different manufacturers, or rather, brands (since some of the brands do not manufacture their water heaters, I am not entirely sure if they were manufacturers) and have been told that using an unapproved water heater is a fire hazard. However, I was unable to get specifics as to why. If someone has that information, I would appreciate it.

If you look at the bottom of some of the water heaters for mobile homes, you will see an intake opening that sometimes (in newer units) will be ducted to underneath or outside the home. Not in all cases, though. I am not sure why. Might be the age of the home.

Local plumbing contractors believe that it is because it is necessary to get HUD approval on a water heater for mobile homes and the manufacturers do not want to have that approval cost tacked onto all of their line. Generally, the water heaters for mobiles costs about $50 more than it's counterpart. The local building departments do not seem to enforce this either.

In any case, like you already pointed out, the label states something like "Not for installation in a manufactured/mobile home." And that is what I put in my report. Along with a photo of the label.

[Dan Harris]

Over the years I replaced a couple hundred MH gas water heaters. The local inspector never questioned if they were approved for MHs, when I remembered to get a permit. :)

The only thing I figured was, the MH ones include an orfice for propane.

Combustion air may be a factor on the older ones. The newer ones have an upper and lower vent in the exterior cabinet doors.

[Peter Taheny]

If you look close the ANSI standards that MH water heaters comply with are different that those for standard residential water heaters. What the differences are I don't know or care.

The majority of states operate under an agreement with HUD becoming the State Administrative Agency (SAA) for manufactured housing in their state, in the states where there is not an SAA HUD will contract with an independent agency. In this role the states write and enforce regulations for the set up, alteration and repair of MHs. The State Administrative Agency (SAA) is a program function of the Manufactured Housing (MH) Section that administers the Department's delegated authority under The National Manufactured Housing Construction and Safety Standards Act of 1974.

Many jurisdictions (CA included) allow the use of standard listed residential water heaters for replacement even though the water heater might have a label noting that it is not approved for manufactured homes. Most times MH approved water heaters are only required for the original construction of the home.

Basically after the first sale of the home, the home is no longer governed by the HUD but by the state (SAA) and the state reports to HUD. Another interesting items is if you look through the ‘Manufactured Home Construction And Safety Standards’ you will find no reference to remodel, repair or alteration except alterations prior to the first sale. And another item is there are many two story HUD code homes but you will find no requirement for rise and run in the HUD code.

California has recently posted the information bulletin from 1988 stating that it allowable to replace a MH water heater with a standard listed residential water heater.



Mike
I might be conducting an all day seminar for CREIA dealing with manufactured housing this coming April in Bakersfield. Suggest you attend.

[Peter Taheny]

Fritz

The point is that in CA listed residential water heaters are allowed for replacement in manufactured home.

Do you check all the listings for all the appliances that you look at.

[Gunnar Alquist]

Peter,

Thanks for that. I have always noted the condition and assumed that the water heaters were incorrectly installed.

My problem is that the manufacturer's are clearly stating that residential water heaters should not be installed in manufactured homes. I believe that I will continue to make my recommendation based on the manufacturer's instructions.