Abstract: A mixer valve includes a rotational assembly for selecting a temperature of the water up to a maximum temperature. The rotational assembly includes a selectable “comfort” temperature indicator, that can be set independently of the maximum temperature, and does not affect the maximum temperature. The valve also includes check valves for preventing cross flow between the hot and cold pipes. A check valve insert is provided which includes a shutoff for the water flow when removing the check valve for service. The shutoff and removal of the check valve can be effected with a single tool.