2ND MAINTENANCE TUNE-UP FOR HEATING SYSTEM. CHECK HEAT EXCHANGER, HIGH LIMIT CONTROL, ALL ELECTRICAL CONNECTIONS, BURNERS, AND BURNER OPERATION. CHECK GAS PRESSURE AND FOR PROPER VENTING. INSTALL 4T HT UV. MADE SURE SYSTEM WAS INSTALL PROPERLY. MADE SURE WORK AREA WAS CLEAN WHEN FINISH. RENEWED SA.