Furnace tune-up and safety inspection. Cleaned and serviced furnace. Last visit to the plan. Tested all mechanical components. Cleaned all sensors. Cleaned all pressure switch hoses out. Cleaned the condensation trap and all hoses out. Tested gas valve and inlet/outlet pressures. Replaced furnace filter and humidifier pad filter that the customer provided. Tested humidifier operation. The system is clean, heating, and operating properly at this time. AC maintenance. Checked refrigeration levels of the AC system. Found refrigerant levels are below freezing for the 3rd time in our history. Took pictures of gauges showing below-freezing coil temp. Giving the Customer multiple estimate options to address the leak issue and other component issues. Found the capacitor is below the acceptable mfd range, and the contactor is making a bad humming noise.