Pentair MasterTemp 400,000 BTU natural gas heaters work fast and efficiently without taking away from your pool’s aesthetics. The new design ensures safety and reliability with a tough exterior and easy to use digital controls. A fully pre-mixed system with a highly efficient air and gas mixture lets MasterTemp heat up fast and efficiently. With a hot surface ignition – no pilot light, and push-button, digital controls, MasterTemp is as easy to operate as your home heating system. User-friendly indicator lights make system operation and monitoring a snap. The easy-to-view, rotating digital display places controls front and center, no matter how MasterTemp is positioned on your equipment pad. The MasterTemp features a cupro-nickel exchanger that stands up to the harshest of applications, like low pH, high flow or heavy use. The heater also features a tough, rust-proof composite exterior that handles heat and weathers the elements. Ensure safe operation through a series of features, including: a water pressure switch that senses the pump is running to prevent overheating, high limit switches assure the heater turns off if water temperature exceeds factory-set limits, manual gas shut-off when service is required, and a stack flue sensor that also guards against overheating. Certified for low NOx emissions and meets strict air quality standards. Includes 2 inch PVC slip unions and operates at 120 or 240 volts.