I was looking at a house but I hesitate to buy it because it didn't have a water heater. It had oil heat and something called a summer winter hookup where supposedly the oil heater heated the water for the house but I don't really understand how. does anyone have this? the house was vacant so there were no occupants to ask about this. I'd hate to buy it and then have to mess with putting in a water heater when it's not even set up to have one. with no tank that I could see, how could it heat enough water at a time? I don't get it. anyone familiar with this set up?