CAME OUT TO SERVICE 13YR HEATING SYSTEM. CHECK THERMOSTAT, AIR FILTER, GAS PRESSURE, HUMIDIFIER, ENERGY CONSUMPTION, HEAT EXCHANGER, HIGH LIMIT CONTROL, FAN CONTROL, AND ALL ELECTRICAL CONNECTIONS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. ADJUST BLOWER COMPONENTS, AND LUBRICATE ALL NECESSARY MOVING PARTS.