Andrew Gabriel wrote:

I have not seen condensing boilers in the US.
Boilers are not common in any case, and the only ones I've seen look
like what we had in the 1950's/1960's. Electric water heating is much
more common than here.

I watch videos from a couple of American builders, they seem to call
them "tankless heaters"

e.g. https://youtu.be/1hdk7cCztPo