Abstract: A bracket to retain an expansion tank in conjunction with a water heater tank may comprise an upright member that extends along the side of the water heater tank and a horizontal member that extends along the top of the water heater thank when the bracket is installed, such that the horizontal member is gravitationally retained against the top of the water heater tank. Straps may be used to retain an expansion tank to the upright member. Magnets, retention straps, and/or legs may be used to retain the bracket in position relative to the water heater tank. Straps, extensions upon which an expansion tank may rest, and retention mechanisms may be used to retain an expansion tank in a bracket.