I notice that a lot of information on HVAC suggests that people have their unit checked before each season to keep it running more efficiently. Is this really necessary? I don't know anyone who does this. My brother called for a check-up a few years ago and the service person acted puzzled. He continually asked if he was experiencing any problems and was told no, "I just wanted to get a check-up." The service person told my brother that unless you are having problems, there is really nothing to check. Last year, we had a mouse removed from our furnace due to odor and I asked if he could give it a check-up and he asked if I was having any problems other than the smell. I said no, and the service person said "then everything should be good." To me, it's like those commercials that say, "ask your doctor," but when you do ask your doctor, they look at you as though you're crazy.