Atwood Mobile has a range of water heaters
. I have an Atwood in my motorhome and an Atwood XT
in a large trailer.
The XT claims equivalent capacity higher than its actual capacity by running at a very high temperature and diluting the output with cold in a fixed ratio to produce a greater quantity of water at a normal "hot water" temperature. This is slick, but it is also less efficient and introduces a mixing valve (visible in the brochure photos) which can fail, plus more plumbing connections.
Non-XT Atwood tank-type water heaters
are conventional, but like the XT they use an aluminum tank to avoid the need for a protective anode; this is a maintenance convenience. They claim other advantages
, but I have not verified their efficiency claim in published specs.
Atwood also has an on-demand
water heater model.