First, an admission against interest
A meaningful share of the 'my door is broken' calls we get end with a technician moving a rake handle away from a sensor, or pressing a button on the wall console. We fix it, the homeowner is relieved and mildly embarrassed, and everyone's day continues. We'd rather save you the service call.
So here are the five checks our own techs run first, in order, when a door opens fine but won't close — or closes partway and reverses. They're free, they take ten minutes total, and they resolve roughly half of these situations. If you get through all five and the door still won't close, the second half of this article covers what it means and what to do.
Check 1: The safety sensors (the #1 culprit)
Near the floor on each side of the door opening are two small 'photo eyes' facing each other, projecting an invisible beam. If anything blocks the beam — a shovel, a trash bin, a leaf, a spiderweb, low sun glare — the door will refuse to close, or will start closing and reverse. This is a safety feature, not a malfunction.
Look at both sensors. Each should show a solid indicator light (colors vary by brand — commonly one amber, one green). A blinking or dark light means blocked, dirty, or misaligned. Clear anything in the beam's path, wipe both lenses with a soft cloth, and check that neither sensor has been knocked crooked — they're mounted on brackets that a bumped garbage can will happily bend. Gently nudge them until the lights go solid, then try the door.
Check 2: Lock mode on the wall console
Most wall-mounted control consoles have a lock or vacation button that disables the remotes — and it is extremely easy to press by accident, often by a child or while carrying groceries. If your remotes and keypad do nothing but the wall button still works (or vice versa), suspect lock mode. Press and hold the lock button for a few seconds to toggle it off, then test the remote.
Check 3: Remote and keypad batteries
Obvious, and therefore skipped by everyone. If the door responds to the wall console but not the remote, the remote's coin battery is the likely suspect — they last a few years and die without ceremony. Keypads eat batteries faster in cold weather. Swap batteries before assuming anything worse.
Check 4: Anything in the tracks
With the door open, look up along both vertical and curved sections of track for obstructions: a stray ball, a dislodged roller, a bird's nest (it happens), or dents in the track itself. Do not reach into or strike the tracks — just look. A door that starts down and reverses at the same spot every time is often meeting resistance at that spot.
Check 5: The manual release wasn't left disengaged
That red cord hanging from the opener rail disconnects the door from the motor for power outages. If someone pulled it — say, during last month's storm — the opener will run merrily along the rail without moving the door. Reconnecting varies slightly by model, but on most: pull the cord toward the door to reset the trolley, then run the opener; it will click back into engagement as the trolley passes.
When it's none of these — and what that means
If the five checks come up clean, the remaining causes are the ones that genuinely need a professional: travel-limit or force settings that have drifted (the opener 'thinks' the floor is somewhere it isn't), a failing logic board, a broken spring or cable changing the door's weight balance mid-travel, or binding rollers and hinges adding resistance the opener interprets as an obstruction.
Two of those — springs and cables — are safety issues, not just convenience issues. If the door feels unusually heavy when lifted manually, hangs crooked, or you can see a gap in the spring coil or frayed cable strands, stop operating the door and call a professional. Those parts are under high tension and are the two repairs we most firmly ask homeowners not to attempt.
One last tip that helps us help you: when you call any repair company, describe what the door does — 'it closes two feet then reverses and the opener light blinks five times' is a diagnosis-grade clue. Blink codes differ by brand, and a good dispatcher can often tell you over the phone what you're dealing with, what it's likely to cost, and whether it's safe to use the door in the meantime.
Frequently asked
Why does my garage door start to close and then go back up?
The most common cause is the photo-eye safety sensors — blocked, dirty, or misaligned. Check that both sensor lights are solid. If sensors check out, the door may be meeting resistance in the tracks, or the opener's travel and force limits may need professional adjustment.
Why won't my garage door close but the opener runs?
If the motor runs but the door doesn't move, the manual release trolley is likely disengaged (the red cord was pulled) — or, more seriously, a spring or cable has failed. If the door feels very heavy to lift by hand, stop and call a professional.
One sensor light is blinking. What does it mean?
A blinking sensor typically means the pair is misaligned or the beam is interrupted. Clear the path, wipe both lenses, and gently adjust the blinking sensor's bracket until its light turns solid. If it won't hold alignment, the bracket or wiring may be damaged.
Is it safe to close the door by holding the wall button?
Holding the wall button overrides the safety sensors — it will close the door, but with the safety system disabled. Use it only when you can see the doorway is completely clear, and treat it as a temporary workaround, not a fix.