CAME OUT ON A SERVICE CALL, NO HEAT. INSTALLED 4 TON HP/COIL. CLEAN AND CHECK BURNERS, AND BURNER OPERATION. CHECK HEAT EXCHANGER, HIGH LIMIT CONTROL, FAN CONTROL,THERMOSTAT, AIR FILTER, AIRFLOW, ENERGY CONSUMPTION, HUMIDIFIER, AND ALL ELECTRICAL CONNECTIONS. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS. EVERYTHING IS RUNNING GREAT.