That will be very inefficient for household use, Ig. Sell it and buy
a new tankless gas heater. They're extremely efficient but cost 2x to
3x that of tank heaters. If you can make a grand off the big one,
you're all set. http://www.rinnai.us/tankless-water-heater

Ig could do something the rest of us can't because our heaters are too
small. Set the temp to just above shower temp maybe 110 degrees.
Considerable improvement in efficiency and he won't run out of hot
water.