Used less than 2 years. Switching to solar so no longer need this unit. Sta-Rite Max E Therm Gas Heater 400,000 BTU Propane are the most unique heaters on the market. Made from a composite shell, the Max-E-Therm utilizes PMG combustion technology to produce the highest efficiency (85%) in its class, while keeping NOx emissions to a minimum. That means less time waiting for your pool or spa to warm up, and more time enjoying it. Features: Lightweight - lightest heater in its class Best in class energy efficiency Compact design - ideal for retro-fit installations Easy to switch - change gas sources with installation of separate orifice Environmentally friendly - all units are low NOx Rustproof housing - sleek, matte black enclosure is made of Dura-Glas® - an exclusive Sta-Rite® material that handles the heat and weathers the elements Lower operating costs - 84% efficiency rating - rated first in its class for highest energy efficiency Custom or retrofit - direct-connects to Sta-Rite® System:3® Mod Media filter or easily fits other systems Certified for outdoor and indoor installations Specifications: BTUH Input : 400000 Cabinet Depth : 31.69 Inch Cabinet Height : 30.03 Inch Cabinet Width : 25.15 Inch Control Type : Digital Flow Rate : 120 gpm Frequency Rating : 60 Hz Gas Type : Liquid Propane Phase : 1-Phase Standards Approvals : CSA Certified, Eco-Select Tubing Material : Cupro-Nickel Voltage Rating : 120/240 VAC Water Connection : 2 Inch