I have dual heaters - old ones. Model 210 from 1990 or so. One of them started leaking, with water going in to the kitchen and under the tiles. The heaters are in the garage. The leak was coming from the bottom of one of the heaters. So I drained it. The draining would not stop till I shut off the cold water inlets of BOTH heaters. Why is that? Will we not have hot water from the non-leaking heater also?