Keep the guides clean
Dust and grit in the side guides make the shutter noisy and slow. Wipe the guides regularly and remove anything stuck in the track.
Watch for early signs
Scraping sounds, uneven travel, a slat that sticks out or a motor that strains are early warnings. Stop using the shutter if it moves unevenly and ask for an inspection.
Leave springs and motors to a technician
Springs and drives are under load. Do not adjust them yourself. A planned service visit is safer and often cheaper than a breakdown during business hours.
