Buderus’ GB142 modulating, gas-condensing boiler has four models supplying from 84,800 to 214,800 Btu/hr. and cascades of up to 16 units for even higher outputs. Its quiet operation — with output modulations between 30% and 100% — is matched to actual heat demand to save energy. It also has an Annual Fuel Utilization Efficiency rating of 95%. The GB142 includes advanced and easy-to-control integrated EMS controls for outdoor reset and control of an optional indirect domestic hot water tank.