Pentair 250,000 BTU Natural Gas Electronic Ignition MasterTemp Heater MasterTemp® Heaters offer all the efficiency, convenience, and reliability features you want in a pool heater, plus a lot more—fast heat-up, compact design, super quiet operation, easy to use, and eco-friendly. An Eco Select™ Choice: MasterTemp® Heater high performance heaters offer best-in-class energy efficiency. Plus, they are certified for low NOx emissions, making them eco-friendly favorites. Features Heats up fast so no long waits before enjoying your pool or spa Best-in-class energy efficiency Manual gas shut-off when service is required Eco-friendly MasterTemp is certified for low NOx emission and outperforms industry standards Rotating digital display allows for easy viewing Tough, rustproof exterior handles the heat and weathers the elements