Caya writes:

Any ideas?

28 KW (37.5 HP) and weighs 30 lbs? Are you mad? That's energy density
comparable to a jet engine. Not something I want running in my house.

To heat water to 120 deg F in a Yankee winter (delta_T = 80 deg F) takes
40,000 BTUs/hour for each gallon per minute. That's 11.7 KW per
gallon/minute with perfect efficiency. So a 28 KW unit (if that much is
to be believed) will get you 2.4 gallons/minute of hot water. After
tempering to bath temperature with cold water, you will be just over the
piddling water-saving "shower" rate of 2.5 gal/min, which will waste
many minutes of your time every day (or however often a rube who is
foolish enough to buy tankless bathes) for the rest of your miserably
shower-impoverished, life.

Also consider that electric demand rates are typically $12 per KW each
month. So to just turn on this 28 KW fantasy costs you $336 per month!
Or it would if your residential electricity weren't subsidized for free
demand. This is after you have paid $1000s to upgrade your electric
service by 100+ amps to operate this rocket engine gadget that runs like
a tricycle with a bent wheel.

Tankless heaters are more expensive to buy, more expensive to own, and
more expensive to operate. Anyone who selling you a different story is
a fraud. This is not a case of sales puffery or exaggeration. This is
outright flim-flam baloney that flies in the face of physics. The
reason the Web sites and newspaper ads look like they were designed by
hillbillies after a quick buck is, they were.