With the BLUE STREAM® energy efficiency concept, Wolf demonstrates that even condensing technology can be enhanced yet further. BLUE STREAM® is based on four key improvements on previous condensing boilers: reduction of power consumption (especially in standby mode), innovative pump control (no overflow valve, no return temperature raising facility), modulating burner (minimum output of 1.8 kW for gas and 6.6 kW for oil, clean combustion, self-calibrating) and intelligent control technology (remote control via smartphone, remote diagnosis, link to ventilation and solar thermal systems).