After filling the fresh water tank and turning the pump on to fill the hot water tank I found that the pump continues to run even after water is running from both the hot and cold tanks and then all taps are shut off. My expectation is that the pump would shut off when all tanks are full and all taps are shut off. The pump continuing to run for 15 minutes is somewhat disconcerting. There are no leaks. Ultimately, I just shut the pump off. Has anyone else had this run-on problem?