The Peerless® PUREFIRE® PF-399, PF-460, PF-850, PF-1000 and PF-1500 gas-fired condensing boilers are available for either natural or LP gas systems; the boilers have a thermal efficiency of up to 96.6%. The direct vent, sealed combustion, commercial-size boilers have ASME and ETL certifications for both the U.S. and Canada. A unique condensate system with built-in neutralizer component and float switch protection is a top feature of this boiler series. Other great features include a high grade stainless steel burner and heat exchanger, 120 volt convenience outlet (PF-399 only), cascade and common vent capability (common venting on PF-850, PF-1000 and PF-1500 only) and LoNOx operation for the good of the environment. The PUREFIRE®’s fully modulating burner assures dependable operation and maximum boiler efficiency. Zero clearance to combustibles, easy access to controls and leveling legs are other standard features that allow for ease of installation and maintenance. The PF-850, PF-1000 and PF-1500 boilers can be stacked to further minimize their small footprint. Boilers are easily converted from LP to natural gas and from natural gas to LP without any additional parts. PUREFIRE® boilers are equipped with a full one-year parts and labor warranty (see “Warranty” section on this site for complete details).