I installed in floor heating tubes in my shop when I built it 3 years ago. I had planned on installing a boiler someday to complete it, however the cost of a boiler is quite high, and I have heard that some guys use hot water heaters instead. This building is for personal use, not commercial. Does anyone know what components I need to install a hot water heater. I have 4 circuits all 330 ft. each in length. The plumber I purchased the pipe from won't even talk about using a hot water heater. Wants me to buy his boiler.