A garage door is very heavy and works with a series of springs, chains, gears and the like and it also has a number of electronic parts that keep it operational or tell it to shut off as needed. Because of this, it's not unusual for something to eventually break so that the door doesn't work at all or acts in a very unusual and confusing way. When you're having problems with your home's garage door, note a few troubleshooting tips so you can address the issues or talk to a contractor about the work that might need to be done.
1. Motor runs for a few minutes, but door doesn't move
If your automatic garage door opener hums and you know it's running but the door doesn't move and the motor shuts off after a few seconds or a few minutes, usually this is a problem with the springs or the chains that move the door. The motor may attempt to operate those springs or chains and when they don't actually move the door, the motor will then switch off to keep itself from being overworked. Rather than checking the motor, check the springs or chains to see if one is broken or if there is no tension. Be careful doing this as garage door springs hold a lot of weight and are very dangerous; call a contractor to replace these for you if needed.
2. Door closes with a bang
Garage doors usually have a tension spring to provide a counterbalance to their weight when they close, and if this spring is broken or the cable attaching the spring to the door is stretched or broken, there is nothing keeping the weight of the garage door balanced. In turn, it closes quickly and may hit the ground with a bang. This too is best left to a contractor as those springs and cables hold a lot of weight that can be dangerous.
3. Closes and then opens
A garage door will usually have a sensor that controls the close limit, or how far the garage door needs to travel to close. If this sensor is damaged, the garage door may reach the ground but assume it's actually hitting something in its path; in turn, it may then reverse course and open. Have a repairperson check these close limit settings or the sensor to which it's attached and see if they need adjusting.
If you need any garage door repairs that you don't know how to handle, don't hesitate to call a professional.