Hello, My yearly maintenance contract costs $199.00, for which I get a twice-yearly visit from a HVAC technician that typically spends just a few minutes and then tells me: "Everything is OK", before going on to his/her next call. Since my Trane equipment is now 18 years old, my intuition tells me that a more thorough tune-up is probably warranted. Do you agree? If so, for the upcoming cooling system, what steps should I insist that my technician follow to make sure my air conditioner is operating at its highest efficiency?