So I think the "General Contractor, suppliers, and manufacturers" needs some schooling! Although if the suppliers and manufacturers only handle boilers, then you know why they think the way they do!!! LOL...Making claims that demand heaters won't last because of short cycling? I wonder how many times a demand heater cycles a day when used in a household of 4-6 people?! If worried about short cycling when used for floor heat, a simple T-stat on the return that has an adjustable differential will control cycle length on the heater! I set mine to 15° differential to control cycle time....
Ourtown, I thought you already put in tankless for floor heat? Maybe thinking about someone else on the forum? Agree with you, boilers are more than 4x that of a demand heater. The last time I looked on Supplyhouse.com, My 199k Takagi was just over $1200. I'm on year 11 with it now! BTW, if you keep any type of heater/heaters under 200k, from what I unsderstand, you don't need to have a Boilers License to install or operate.