Product Information:This heater meets California emissions and safety standards, and is suitable for use in all 50 states. Ecofriendly, ultrahigh performance in a compact and quiet design, the MasterTemp is certified for low NOx emissions and outperforms industry standards. The compact design allows for smaller overall equipment pads that wont intrude on your poolscape. A fully premixed system with a highly efficient air and gas mixture lets MasterTemp heat up fast, so there is no long waits before enjoying your pool or spa.With a hot surface ignition (no pilot light) and pushbutton, digital controls, MasterTemp is as easy to operate as your home heating system. Plus, userfriendly indicator lights make system operation and monitoring a snap. The easytoview, rotating digital display places controls front and center, no matter how MasterTemp is positioned on your equipment pad.Safe operation is assured 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 shutoff when service is required and stack flue sensor also guards against overheating.Due to the fact that this heater is MADE TO ORDER, allow at least 10 days for assembly. If a return is requested and accepted there will be a substantial restocking fee. Please be sure to choose the correct heater before purchasing.