Why your garage door won't open
A door that will not open is nearly always telling you exactly what is wrong, you just have to know its language. Here is the diagnostic we run in our heads on the phone, written down symptom by symptom. Match yours, read the likely cause, and mind the two situations where the right move is to walk away from the door.
Thirty-second triage
| What you have | Most likely story | Read on at |
|---|---|---|
| Nothing: no sound, no light | Power or opener supply | Symptom 1 |
| Opener hums or clunks, door stays down | Spring or drive problem | Symptom 2 |
| There was a loud BANG earlier | Snapped torsion spring | Symptom 3 |
| Lifts a little, stops or reverses | Balance or force limits | Symptom 4 |
| Door is crooked or jammed | Cable or track | Symptom 5 |
| Opens fine, refuses to close | Safety beams | Symptom 6 |
Symptom 1: silence. No movement, no sound
Start boring: is there power? Check the opener's plug at the ceiling outlet, the switchboard, and whether the courtesy light on the opener responds to anything. Try the wall button, not just the remote; a flat remote battery is the cheapest repair in this trade, and the wall button bypasses it. If the wall button wakes the opener but the remote does not, it is the remote or its coding. If nothing responds on a powered circuit, the opener's own electronics have likely failed, and that is a visit.
Symptom 2: the opener hums, clicks or clunks, but the door stays down
The motor is trying and something is not answering. Three usual stories. The drive trolley has stripped or disconnected, so the motor runs without moving the door; check whether the red release cord has been pulled by a broom handle or a boot at some point. The second story is a seized or dry mechanism binding the door in place. The third, and the one that matters, is a snapped spring: the opener strains against a door that suddenly weighs its full real weight, and most will refuse or give up mid-lift. Look up at the shaft above the door; a torsion spring with a visible gap in its coils has already told you everything. Stop pressing the button; an opener fighting a dead-weight door strips its own gears.
Symptom 3: there was a loud bang, and now the door is dead weight
That bang was almost certainly the torsion spring letting go; people regularly mistake it for something hitting the roof. The spring holds the door's real weight, often north of a hundred kilograms on a big door, so with it gone the opener cannot lift, and neither should you: a one-handed lift that worked last week is now a two-person dead lift with nothing holding it up if you let go.
The rule that matters: every bracket, bolt and cable on the spring assembly stays exactly where it is. Parts of a failed spring system can still hold stored tension, and undoing the wrong bracket releases it all at once. Spring work is a technician's job, and we wrote a plain-terms explainer on why.
Symptom 4: it lifts partway, then stops or rolls back
Two candidates. First, the door's balance has drifted, springs lose tension gradually, and the opener's force limit decides the door is "too heavy" partway up and backs off. Second, something physical: a fatigued roller catching at the same spot in the track, a bent track section, or debris in the track, and in dusty country debris means dust packed hard where the rollers ride. If the door stops at the same height every time, suspect the track at that height; if it varies, suspect balance. Both are service-visit fixes, and both get worse with force.
Symptom 5: the door is crooked, or jammed in its tracks
A racked or crooked door usually means a lift cable has come off its drum or snapped on one side, so one side of the door is being lifted and the other is not. It may jam solid mid-travel. Do not force it, and do not pull the manual release while the door is part-open: with a cable off, releasing the opener can let the door fall. Leave it jammed; that is a same-visit repair for the right tools and a bent-track write-off for a crowbar.
Symptom 6: it opens fine, but will not close
An automatic door that opens but refuses to close is nearly always its safety beams, the two little sensors near floor level either side of the opening. They are doing their job on bad information: knocked out of alignment by a bin or a boot, wired loose, or blinded, and out here blinded usually means dust on the lens or low westerly sun straight into it. Check the sensor lights, wipe the lenses, and see if the door will close on a held wall button. If the beams check out and it still refuses, the opener's logic or limits need a professional look. The auto-reverse behaviour is a safety function required of compliant openers under the Australian standard for garage door openers (AS/NZS 60335.2.95), so the honest advice is to fix the cause, never to bypass it.
Getting the car out: the manual release
Most openers hang a red cord from the drive rail. With the door fully DOWN, pulling it disconnects the door from the opener so the door can be lifted by hand, if the springs are intact, it will lift as easily as a manual door. If the spring is snapped, the release will not make the door liftable, it will make it loose. So: bang plus stuck car equals tell us the car is trapped when you enquire; that detail changes how the visit is planned.
What we will ask when you enquire
- What the door does when you press the button, in the words above.
- Whether there was a bang, and when.
- Door type: sectional panels, a rolling curtain, or a one-piece tilt.
- Roughly how wide, single, double, or a proper shed span.
- A photo, if you can take one without going near the hardware.
That is enough for us to arrive with the right parts most of the time. Send the enquiry, or if the property runs more than one door, put two minutes into the Door Muster and send the lot.
References
- AS/NZS 60335.2.95 (Standards Australia): the safety standard covering automatic garage door openers, including the auto-reverse and entrapment-protection behaviour described above.
- ACCC Product Safety: garage door openers: recall notices and safety information for openers sold in Australia; worth a check if your opener is older or second-hand.
- NSW Government: electrical work licensing: why the 240-volt side of any opener repair or install is a licensed electrician's work in NSW.
