The hot water needs of a residence are met by a 20-gal hot water heater rated at 6000 btu/h. the tank is initially filled with hot water at 175°f. as the hot water supply is drawn from the tank, it is replaced by cold water at 50°f at a flow rate sufficient to keep the tank full at all times. during this replenishing process in the tank, the water is heated at the water heater’s full rated capacity. water this hot is great for washing clothes or dishes, but it is far t