Do I need a pressure tank for my water heater?

When is it necessary? An expansion tank is always strongly recommended if you have a closed loop system caused by any type of pressure control valve or valve installed in the domestic water supply line. A common analogy is compared with maintaining a high water pressure in your home at high blood pressure.When should it be done? If your house's water supply line has a check valve or pressure regulating valve installed, an expansion tank is highly recommended. Having high water pressure in your home is the same as having high blood pressure.