Arguably,
the most common type of water heater is the traditional tank hot water heater. The unit consists of a storage tank
that is designed to hold a fixed capacity of water, which in the U.S is
typically rated in gallons. When the hot water tap from a faucet is opened,
water flows from the top of the tank through piping to the faucet. As that
water exits the tank, cold make-up water enters the tank near the bottom. As
the cold water mixes with the hot within the tank, the temperature of the water
in the tank begins to drop. When the temperature falls below the set
temperature on the tank’s aquastat, the burner unit fires to begin reheating
the water in the tank.
Standard
tank water heaters are available in a variety of standard sizes to match the
unit’s capacity to the hot water demands or consumption. Depending on the
material used in the construction of the tank, the expected life can vary. Many
units include a sacrificial anode to minimize corrosion of the tank components.
Regular flushing out of sediment is recommended as part of the routine
maintenance of traditional tank water heaters.
