I’ve had my air conditioner for 9 years, and I just had it serviced – for the first time. I know better than that. I think air conditioners tend to get neglected. It needs a periodic tune-up/cleaning which prolongs its life and efficiency, just like your furnace. The trick is, it should be done in the warmer months. Since fall is here, it might just be a good time to have both your furnace and air conditioner serviced.