gas or electric? if electric just forget it, unless your willing to
upgrade your main service to 200 amps just for heating water. can cost
gas? delay from valve open to hot water arrives, heater must detect
water use then turn on burner. you will waste water.
with low flow valve open a little to wash dishes may not be enough to
trip on burner, cold water a result.
if your tankless needs line voltage to operate a power outage means no
hot water at all. a standard tank still has a tank full to give, for
say 2 quick showers.
tankess warranty is no longer than a regular tank. you need qualified
service people they are complex. standard tanks are highly reliable
till they leak, at which point you replace them...... nearly no
if you live in a area that gets cold, incoming cold water can cause
tankless troubles when water gets really cold. around here it bottoms
at about 40 degrees.
the tankless savings are bogus, regular tanks standby losses are
really low, take a look at the energy guide. in the lifetime of a
tankless you will save little because of the large up front cost.
oversize gas line, high capacity flue/
in the winter standby losses help heat your home
endless hot water can get some folks to live in the shower, driving up
water and gas use........ teenagers are the worst.