Electric combi boiler

Buy offer Details

Dear Sir/Madam,
Hi, I own a few real estate properties in the US (New york state) and I would like to fit them with electric combi boilers.
I want to try this on one property and then extend to the others. This property has 5 apartments (around 800 square feet or 75 square meters, each apartment). The apartments are currently running on an oil boiler and one oil hot water heater. The heat is provided through baseboards throughout the apartments, so I have hydronic system in place.
My idea is to install 5 units of electric combi boilers in each apartment and just hook them to the existing hot water supply and hydronic heating (baseboard elements).
I am not a plumber or installer, and of course I would get one to install everything, my only concern is that the electric combi boilers are not incredibly popular here.
- What units would you recommend (capacity)
- What is the cost?
- What is the shipping?
- What are the warranties, and how do they work if the equipment breaks down?
- How would you service it from so far away?
Regards,
Colin