Today, I performed a preventive maintenance and tune-up on both a Lennox and a Carrier air conditioning system. The service involved thorough cleaning of the condenser coils, replacing air filters, and calibrating the thermostats for optimal performance. I conducted a detailed inspection of the electrical components, tightening connections and verifying capacitor functionality. Refrigerant levels were checked and adjusted to manufacturer specifications using a refrigerant manifold gauge set. The systems were tested under load conditions to ensure efficient and reliable operation.