LochinvarR Corp has introduced the Efficiency+R 100 residential gas boiler. Ideal for residential and light commercial use, the high-efficiency, direct-vent boiler is the latest in Lochinvar's line of high-efficiency water heaters and boilers. The Efficiency+ 100 has a standard two-stage burner that saves fuel by closely matching output to system demand, and allows a longer burner-on cycle to maximize operating efficiency. The Efficiency+ 100 has an 84% thermal efficiency rating, integrated boiler control and internal diagnostic panel. Lochinvar Corp.