UL 307

Gas Water Heaters for Manufactured Homes

Manufactured homes get delivered with all manner of unique requirements, from hurricane anchors to specific electrical standards. It should not be a surprise that gas water heaters fall into the same category. What is a surprise is the dearth of information that a home inspector can locate on the subject, hence today's article.

The short version is that the types of water heaters permitted to be installed in a manufactured home is severally limited. Per the HUD standards that govern the installation of the water heaters, they must comply with UL 307B, UL Standard for Safety Gas-Burning Heating Appliances for Manufactured Homes and Recreational Vehicles. Having looked up the relevant standard, which is no easy feat, I now understand why so little information is available. UL 307B sells for $894! Sorry, but that is not in this home inspector's budget.

Buried in there is the warning. Good luck to the home inspector that wanted it to be easy!

Buried in there is the warning. Good luck to the home inspector that wanted it to be easy!

To be installed into a manufactured home, all water heaters must conform to the UL standard. From an inspection standpoint, my job gets much easier by knowing one critical piece of information. All water heaters in compliance must be marked with a HUD tag. Second best is that some heaters, not approved for use, will say so in fine print on the side of the tank.

There are a couple of visual clues, too, for the installation. Manufactured home water heaters have the cold water inlet connection on the side and the hot water outlet connection on top. Residential water heaters have all connections on the top of the tank. Also, these heaters are of the direct vent type.

Due to the different standard, these heaters are as much as twice as expensive to replace than traditional heaters. This becomes important in my area as we have quite a few aging neighborhood parks. Golden Hills in Pullman is one example, as is Robinson Park in Moscow. While the majority of the heating appliances are electric, about fifteen percent are gas-fired.

As an inspector, I need to be alert to the differences as the current crop of heaters gets retired and new ones get installed. For real estate agents, an awareness of the increased cost is something to be mindful of when negotiating deals. In both cases, the safety of our home owners is paramount.