Specifications include, but are not limited to: HOT WATER BOILER TRIM: A. ASME rated pressure relief valve, 30 psig (207 kPa).; B. Combination water pressure and temperature gauge.; C. Low water cut-off to prevent burner operation when boiler water falls below safe level.; D. Operating temperature controller with outdoor reset to maintain boiler water temperature.; FUEL BURNING SYSTEM: A. Burner Operation: On-off with low fire position for ignition.; B. Gas Burner: Atmospheric type for propane adjustable combustion air supply, pressure regulator, gas valves, manual shut-off, intermittent spark or glow coil ignition, flame sensing device, and automatic 100 percent shut-off.; C. Gas Burner Safety Controls: Energize ignition, limit time for establishment of flame, prevent opening of gas valve until pilot flame is proven, stop gas flow on ignition failure, energize blower motor, and after air flow proven and slight delay, allow gas valve to open.; D. Controls: Pre-wired, factory assembled electronic controls in control cabinet with flame scanner or detector, programming control, relays, and switches. Provide pre-purge and post-purge ignition and shut-down of burner in event of ignition pilot and main flame failure with manual reset.; REPLACEMENT BURNER FOR EXISTING BOILER TO REMAIN: A. Input Firing Rate (mbh):379-476.; B. Fireing Mode: On-Off or On-Off with Low Fire Start.; C. Fuel: LP Gas; D. Required Gas Supply Pressure: 6" water column standard; E. Input Voltage: 120/1, 5.3 amps; INSTALLATION: A. Install in accordance with manufacturer's instructions.; B. Provide connection of liquified petroleum gas service in accordance with requirements of NFPA 58 and applicable codes.; C. Pipe relief valves to floor.