I have a tankless Water heater. We had a problem at first one of the elements burned out but the manufaturer sent us a new one immidiatley. We have it heating our whole house and I think its great. We have a small house and were space is a concern this option worked out perfectly. Make sure you have enough room in your electrical box for 2-40 amp double pole breakers. I would not reccommend one for a large house with many ocupants. maybe one large one and they sell individaul ones for a large tub or laundry. That might be the way to go.