CLEAN AND CHECK HEAT SYSTEM. CHECK THERMOSTAT AND AIR FILTER. INSTALLED A 3.5T HT 12YR P&L. MADE SURE SYSTEM WAS INSTALLED PROPERLY. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. CHECK ALL ELECTRICAL CONNECTIONS. CHECK BURNERS AND BURNER OPERATION. MADE SURE WORK AREA WAS CLEAN WHEND JOB WAS FINISHED.