2ND MAINTENANCE TUNE-UP FOR 2UNIT, 5YR AND 8YR FOR HEATING SYSTEMS. INSTALLED 2 BASIC ADC AND EARNED 2 RENEWED SA AND 2 REWASHABLE FILTERS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK HEAT EXCHANGER, HIGH LIMIT CONTROL, THERMOSTAT, AIR FILTER, AIRFLOW, HUMIDIFIER, GAS PRESSURE, FAN CONTROL, AND ALL ELECTRICAL CONNECTIONS. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS.