Why does my garage opener run but the door won't move?
Updated August 2026
When the motor hums and the rail turns but the door just sits there, the answer is almost always the emergency-release trolley has been pulled and disconnected from the door. Someone pulled the red cord, or it snagged, and the opener is now driving a disconnected carriage. Re-engage it by pulling the release cord toward the motor head until it clicks, then run the opener to relatch. That free, two-minute fix solves the majority of these cases.
Safety first: if the opener runs and the trolley moves but the door is dead weight, suspect a broken spring and stop pressing the button. Forcing an opener against a door with a broken spring burns out the motor and can send the door crashing down. Spring replacement is not a DIY job: a wound spring stores enough energy to cause serious injury, so leave that to a technician with the right tools.
Causes, most likely first
| Cause | How likely | The fix | Typical cost |
|---|---|---|---|
| Emergency-release trolley disengaged | Most common | Pull the red release cord toward the motor until it snaps into position, then cycle the opener so the carriage re-latches to the door. | Free |
| Stripped trolley or drive gear | Common | The nylon carriage or main drive gear wears its teeth so the motor spins freely; replace the gear kit. | $20–80 part |
| Broken chain or belt | Occasional | A snapped or derailed chain or belt lets the motor run with nothing to pull; re-thread or replace it. | $30–150 |
| Sheared or broken spring | Occasional | With a broken spring the door is dead weight, so the trolley moves but the door will not budge; replace the spring first. | $200–400 |
| Door locked or seized on the track | Rare | A thrown manual deadbolt or a jammed roller holds the door while the opener strains; unlock it and free the track. | Free |
Check these first
- Look for the red emergency-release cord on the trolley; if the carriage is disconnected, pull the cord toward the motor to re-engage, then run the opener.
- Pull the release cord and try lifting the door by hand: if it is very heavy or will not stay open, a spring is likely broken.
- Check for a thrown manual lock or deadbolt that is physically holding the door shut.
- Listen to the motor: a free-spinning whir with no rail movement points to a stripped gear or a broken chain, not the trolley.
- Inspect the chain or belt along the rail for a break, a derailment, or heavy slack.
Prevent it next time
The trolley and drive parts wear faster on a door that is out of balance, so the best prevention is keeping the door itself tuned. Test the opener's safety reverse and balance on the recommended interval, and keep the rail lubricated so the trolley is not fighting friction. When the gears or chain finally wear out, our repair-or-replace opener guide helps you decide, and what a garage door opener is explains the parts.
When to call a pro
Call a technician when re-engaging the trolley does not help and the motor still runs with no movement, which means a stripped gear, a broken chain or belt, or a failed spring. A drive-gear kit runs $85 to $200 installed, a chain or belt replacement $100 to $250, and a spring pair $200 to $400. If the opener is over 12 to 15 years old and the gears are shot, replacing the whole unit for $300 to $600 often beats repairing it.
Most of the causes above are maintenance problems wearing a disguise. OnOtto keeps the boring prevention on schedule so the 2 a.m. version doesn't happen.
Stop chasing symptoms, free for 30 daysFrequently asked questions
How do I reconnect the garage door after pulling the emergency release?
Pull the red release cord straight down and toward the motor head; on most openers this re-arms the trolley latch. Then press the wall button or remote to run the opener: as the carriage travels, it clicks back onto the trolley and reconnects to the door. If it will not relatch, make sure the door is fully closed first, then cycle the opener. The whole process is free and takes a couple of minutes once you know which way to pull the cord.
Why does my opener work sometimes but not others?
Intermittent movement usually means a drive part is on its way out rather than fully failed. A trolley gear with partly stripped teeth grabs on some cycles and slips on others, especially as it warms up or works against the door's weight. A stretched chain can catch and skip. Cold weather can stiffen a marginal spring so the door binds only on cold mornings. Intermittent failure is your cue to service it soon, before it strands the door open or your car inside.
Can I still use my garage door if the opener won't move it?
Yes, in most cases you can operate it manually. Pull the emergency-release cord to disconnect the opener, then lift the door by hand. If it glides and stays open, the problem is in the opener's drive, and you can use the door manually until it is repaired. If the door is extremely heavy or slams down, stop: a spring is likely broken, and a door with a broken spring is dangerous to lift by hand. Leave it down and call a pro.