1ST 13 POINT MAINTENANCE TUNE-UP UNDER SERVICE AGREEMENT FOR HEATING UNIT. FOUND MULTI ISSUES, REPLACED CONTACTOR PER WTY. INSTALLED PREMIUM 4T FURNACE 12Y PNL. MADE SURE EQUIPMENT WAS INSTALLED PROPERLY AND WORK AREA WAS CLEAN WHEN FINISH. CHECK BURNERS AND BURNER OPERATION. CHECK HEAT EXCHANGER, HIGH LIMIT CONTROL, FAN CONTROL, THERMOSTAT, AIR FILTER, AIRFLOW, GAS PRESSURE, PROPER VENTING, AND ALL ELECTRICAL CONNECTIONS. EVERYTHING IS RUNNING GREAT.