Right Wayne, The modulating burners go from something like
18,000-190,000 Btu for the Takagi, My little Bosch does something like
The Energy Factor is a True rating nobody making a tank wants to
discuss, and few consumers are smart enough to ever check, that is your
true rating. Plus rated unit Efficiency. The true tank standby loss is
excessive and pipe heat loss im sure not included as very few people are
smart enough to install thermal couplings on there water heaters.
Now consider tankless 30 year life, no tank to rust out, its all copper
Now consider tanks scale. Rated efficiency is downhill from year one, I
just removed a 20 yr old tank with 12" of hard scale, now that lowers
efficiency alot, tankless do not build heavy scale, but should be
delimed every few years.