·92.5% Annual Fuel Utilization Efficiency (AFUE) ·Sealed combustion ·Direct-vent ·Cast-aluminum mono block heat exchanger ·Integrated modulating boiler control with high limit and probe type low water cut-off ·Direct spark igniter ·Modulating burner, automatic gas valve and blower ·Swing out control panel for easily accessible components ·Safe, economical CPVC and PVC vent pipe ·Natural gas or propane