Purchasing a Garage Door is a large investment for your home and is virtually maintenance free, however lubing the rollers, track, springs and bearing plates twice a year with a garage door approved lubricant is a good preventive maintenance.
To wash the door, use standard car wash soap and rinse with clean water.
Garage Door Opener maintenance should be done periodically, checking the eye beams for dust, debris and other foreign objects. The door will not close unless the eye beams are aligned and free of obstructions. In the event the door will not close, press and hold the wall button this is the safety override, until the door is completely closed.
No other maintenance is required on residential openers other than a screwdriver opener, which requires opener approved lube on the screw once a year.