A garage door that slams shut is a safety problem — stop cycling the opener and keep people clear of the opening. Sudden slamming, reversing, or a door that feels extremely heavy usually points to springs, cables, sensors, or force settings, not a mystery motor failure. Homeowners often search “garage door slams shut” after exactly this kind of scare.
Start with safe checks only: confirm power, look at the photo-eye lenses near the floor, and note whether you heard a bang. Do not wind torsion springs or force a crooked door. For spring-related symptoms, read broken spring signs before you attempt DIY fixes.
An opener is not designed to lift an unbalanced door. If the door feels heavy when disconnected, treat it as a spring or cable issue and book professional repairs. If a vehicle is trapped or the home is unsecured, call for emergency repairs.
If you live in The City and need help with your garage door or entry door, ABC Company LTD is here to help. Request a quote or call if the door is unsafe to operate. See also garage door cable problems.