ENERGY STAR HIGH EFFICIENCY MODELS GAS BOILERS MAHF 125 MACF 150 MAHF 165 MACF 205 Utica UBSSC-050 Utica UBSSC-075 Utica UBSSC-100 Utica UBSSC-150 Utica UBSSC-200 Utica UB90-50 Utica UB90-75 Utica UB90-100 Prestige Solo 60 Prestige Solo 110 Prestige Solo 110P Prestige Solo 175 Prestige Solo 250 Prestige Solo 399 Challenger Combi CC 85 Challenger Combi CC 105 Challenger Combi CC 125 Instinct Solo 110 Instinct Solo 155 Instinct Solo 199 Instinct Combi 155 Instinct Combi 199 OIL FURNACES RSM 600 RSM 600 ECM