You've got the right idea of maybe using more than one. See Takagi-usa.com.
They have support in Canada. I'm happy with one that I installed.

Dave


In article ,
lid (cthorne111) wrote:

I was wondering if anyone in a cold climate (Canada or likewise) has
used the tankless heaters. I was thinking of getting two to replace
an old hot water heater but want to be sure this will get the water
hot enough. The cold water temp from the tap here is 42F.