INSTALL 4 TON 3PIECE CONVER DUEL FUEL 10YR P 5 YR L. MADE SURE SYSTEM WAS INSTALL PROPERLY. CHECK GAS PRESSURE AND FOR PROPER VENTING. CHECK THERMOSTAT, AIR FILTER, CHECK ALL ELECTRICAL CONNECTIONS. MADE SURE WORK AREA WAS CLEAN WHEN FINISH. EVERYTHING IS WORKING GOOD.