Abstract: Examples of a protection valve and a system of protection valves are provided to meet the water needs of a building, while reducing the risk of pipe bursting caused by water freezing in a domestic water system. In response to freezing temperatures, the protection valve/system actuates from run mode to protection mode. In protection mode, the protection valve/system inhibits water from flowing into the domestic water system and also drains water from it. Advantageously, draining the water reduces the likelihood of ice forming in the domestic water system. Even if ice did form, the protection valve/system opens the domestic water system to a drain, reducing the likelihood that water pressure can build up high enough to cause a rupture. Even if there is a rupture, the protection valve/system in protection mode inhibits water from flowing into the domestic water system and out through the rupture.