Do I need / what is a thermal expansion tank?

Bradford White always recommends an installation that allows for thermal expansion whether through an expansion tank or other means. It reduces the stress on your hot water system and its various components including pipes, fittings, fixtures, and even your appliances. A thermal expansion tank may be also required to meet your local plumbing codes. If the water heater is installed in a closed water supply system, such as the one having a back-flow preventer in the cold-water supply, provisions should be made to control thermal expansion. DO NOT operate the water heater in a closed system without provisions for controlling thermal expansion. A plumbing professional can assess your specific system and determine during installation how best to control thermal expansion. Need a plumbing pro? Find one here.