One way to tell if you need to call a garage door service is if the door is not opening or closing as it should. If you hear a loud creaking sound or any unusual noise when attempting to open or close the door, it is usually a sign that something is wrong and the garage door needs to be serviced.
The door should close firmly, and if it does not, it is likely that the springs, roller, tracks, or cables need to be replaced. If it opens too slowly or quickly, tests need to be performed to find out why so appropriate repairs can be made.
If the garage door opener starts to malfunction or does not produce any sound at all, it is time to call for service. If you set your garage door opener and then it does not stay put, the problem could be with the limit switch, chain, or belt, and need to be inspected and adjusted. If your remote control is broken, you need to have the entire unit replaced by an experienced professional.
Another way to tell if you need garage door service is if you notice damage to the material like dents, cracks, broken rollers, scratches, rips, or splits. These can be signs of a mechanical problem that needs to be addressed and fixed right away.