The Rheem-Ruud AP14339D-1 Gas Control Thermostat is a replacement gas control component designed for compatible Rheem and Ruud natural gas water heaters. It regulates gas flow to the burner based on the selected water temperature, helping maintain a consistent hot water supply. The thermostat monitors water temperature and controls burner operation to meet heating demands. Its reliabl... https://www.partshnc.com/ap14339d-1-rheem-ruud-gas-control-thermostat-ng