Ideally, if your air conditioning both heats and cools your home, you should have maintenance performed in Autumn and Spring, this will ensure your system runs as efficiently as possible.
Ductwork leaks will cause inefficient operation of your unit and increases your energy bills. A ductwork inspection is carried out during your A/C service.
You do not want your heating or cooling to fail when you need it most during the peak of winter or summer.