A plumbing system pressure protection valve assembly that utilizes a unitary body to connect a hot water tank to a cold water supply, a vacuum breaker, and an expansion tank. The assembly includes two ball valves coupled to the unitary body to isolate the hot water tank from the cold water feed and to isolate and permit draining of the expansion tank. The assembly also includes a rod and foot coupled to a tab on the unitary body to provide support for the expansion tank service valve assembly.