Garage Door Not Opening: How to Diagnose and Fix Fast
Most jammed garage doors aren’t dead — they’re just waiting for the right nudge. In fact, once you know where to look, freeing a stuck door usually takes less than fifteen minutes.
Start with the obvious wins: confirm the opener is getting power, make sure the lock or ‘vacation’ button isn’t engaged, and swap the remote battery. If those three ticks don’t put the door back in motion, pause before grabbing a spanner. The only hard-and-fast rule is never touch springs or cables under tension unless you’re trained – they can let go with enough force to maim. The guide that follows walks you through a safe, step-by-step flow from the simplest checks to the trickier fixes, so you can decide what’s DIY-friendly and when to call a New Zealand technician.
Step 1 – Make Safety Your First Move
Before picking up a spanner or poking around inside the tracks, give safety the respect it deserves. A garage door looks harmless enough, yet the moving parts are loaded with tension, weight, and mains voltage. One reckless tweak can turn a quick fix into an ACC claim, so slow down, read the notes below, and gear up properly before you touch a thing.
Know the risks before you touch anything
A standard domestic roller or sectional door tips the scales at 90–150 kg. That mass is counter-balanced by torsion or extension springs wound tight like a coiled snake. If a spring or cable lets go unexpectedly, it can whip with enough force to break bone. Add 230 V supply to the opener head and you’ve got electricity in the mix as well.
Always disconnect the opener at the wall socket – or flick the breaker – before you start troubleshooting. Keep hands clear of the drum wheels and spring shaft unless the tension is fully released by a qualified tech.
Gather basic safety gear
Treat the job like any other bit of DIY around the house:
- Closed-toe shoes or boots with decent grip
- Leather or cut-resistant gloves for sharp edges on tracks and panels
- Safety glasses to stop grit or broken spring fragments reaching your eyes
- A sturdy A-frame ladder that locks out securely
- Torch or head-lamp so you can actually see inside the tracks and behind the opener motor
A few minutes kitting up beats hours in A&E.
Identify red-flag situations that require a technician
Certain faults are non-negotiable:
- Visible 50 mm gap in a torsion spring or a hanging extension spring
- Frayed or dangling lift cable, or the door sitting crooked in the opening
- Loud bang heard just before the door stopped working
- Smoke or burning smell from the opener motor housing
If any of these crop up, stop immediately, block pedestrian access to the garage, and ring a Worksafe-registered garage-door service. Some jobs simply aren’t worth DIY pride.
Step 2 – Run the Quick Power and Lock Checks
Nine times out of ten, a “garage door not opening” episode boils down to an easy-to-miss power hiccup or a lock that’s quietly doing its job. Before diving into remotes or mechanics, rule these out — it takes less than a minute and costs nothing.
Confirm the opener actually has power
Plug a lamp or phone charger into the same socket as the opener. If it stays dark, reset the RCD or breaker on your switchboard and try again. Still dead? The opener’s internal fuse or PCB may have blown — jump ahead to Step 6.
When the outlet tests fine, glance at the small LED on the motor head.
- LED on: mains power present.
- LED dim or off: suspect loose plug, tripped surge board, or cooked transformer.
Battery-backup models will often beep once a minute and show a yellow light when running off reserve power, so mains could still be out even though the door tries to move.
Find and disable all lock functions
Modern wall consoles hide a “Lock”, “Vacation” or padlock icon button. Hold it for three seconds until the indicator light switches off; now test the door.
On roller doors, check the inside slide-bolt or external barrel lock is fully retracted. A half-turned key is enough to jam the curtain against the guides.
Sectional doors sometimes have an internal dead-lock handle — verify it’s vertical (unlocked) before continuing.
Do a five-second light test
Press the wall button and watch the opener light.
- Light turns on, motor silent → drive fault (skip to Step 6).
- Light off, no click → control circuit still locked or powerless.
Either way, you’ve now cleared — or pinpointed — the simplest obstacles in under five minutes.
Step 3 – Rule Out Remote, Keypad, and Wall Button Faults
Power is good, the lock is off, yet the garage door is not opening. The next weakest link is usually the gadget in your hand—or the bit of wire on the wall. A flat coin cell or scrambled code will stop an otherwise healthy system in its tracks, so tick off the quick tests below before grabbing tools.
Swap batteries and test range
Pop the cover off the remote or wireless keypad and replace the battery (most NZ units use CR2032 or A23 cells). Observe polarity—+ faces the spring on many remotes. Test the door while standing 2 – 3 m away, then again at 7 m. If the door responds only up close, the battery was failing.
Wall buttons are low-voltage and don’t need batteries, but some models have a coin cell for back-light—change it while you’re at it.
Re-programme or reset the transmitter
Lost power or a power surge can wipe rolling-code memory. Re-pair the remote:
- Hold the opener’s “Learn” button until its LED blinks (≈6 s).
- Press the remote button twice; LED turns solid when stored.
- Repeat for each handset or keypad.
Most NZ openers use 433 MHz or 315 MHz rolling codes; mixing frequencies won’t work, so match the branding or model number.
Eliminate interference and wiring issues
If fresh batteries and re-coding fail, look for electronic clutter:
- LED bulbs, Wi-Fi routers, or baby monitors near the motor can swamp the RF signal—unplug them briefly and retest.
- Metal cladding or a parked ute can block line-of-sight; step inside the garage to rule that out.
For a hard-wired wall switch, inspect the twin cable back to the opener. A staple through the sheath or corrosion on the terminals can create an open circuit—re-strip and re-tighten if needed. When none of the controls wake the motor, jump to Step 6; the fault lies deeper in the opener itself.
Step 4 – Inspect Safety Sensors and Photo-Eyes
If the remotes are talking but the garage door is not opening, the culprit is often the small infrared “eyes” mounted near the floor. When these sensors can’t see each other, the opener logic refuses to drive the door for safety reasons. A 60-second wipe-down and tweak is all it takes to rule them out.
Clean and realign the lenses
Dust, cobwebs, and the odd rugby boot scuff will fog the beam. Gently wipe each lens with a lint-free cloth dampened in mild glass cleaner. Both brackets should sit parallel, 100–150 mm above the concrete, pointing straight across the opening. A bubble level or simply sighting one hood to the other will do.
LED indicators tell the story:
| Sensor LED | Meaning |
|---|---|
| Solid | Beam clear – OK |
| Flashing | Misaligned or dirty lens |
| Off | No power / broken wire |
Adjust until both lights glow solid.
Test the sensor circuit
Press the close button, then deliberately block the beam with a broom handle. The door should halt or reverse. If it already refuses to open, bypassing the beam won’t fix it, but a dead LED suggests broken wiring back to the opener. Check for pinched or chewed low-voltage cable.
Bypass only for diagnosis (not as a fix)
For a quick confirmation, disconnect the two sensor wires at the opener terminals and join them together with a small jumper. Operate the door once. If it now moves, sensor alignment or wiring is at fault; restore the original wiring immediately. Leaving the system bypassed breaches NZ safety standards and voids most opener warranties.
Step 5 – Examine Mechanical Components for Damage or Obstruction
If electricity and electronics check out, move on to the hardware that actually lifts the door. A five-minute visual scan with a torch can reveal snapped metal, bent steel, or a stray cricket bat wedged in the tracks. Keep fingers clear while you look—if something has failed, the door may be sitting in an unstable state.
Springs: the most common mechanical failure
Stand inside with the door shut and eyes level with the spring set. A torsion spring with a clean 50 mm gap or an extension spring hanging slack is broken—full stop. When this happens the opener can’t overcome the extra 40–60 kg now un-counterbalanced, so it hums then quits. Spring replacement is never a DIY job; professionals use winding bars and torque charts, and the typical New Zealand bill is $350–$550 including parts.
Cables, rollers, and tracks
Next, inspect the lift cables that wrap around the drum wheels. Frayed wires, bird-nest loops, or a cable off its drum are red flags demanding a tech. Rollers should sit square in the tracks; a popped nylon wheel or a bent hinge bracket will jam the curtain. Light track kinks can be straightened with adjustable pliers, but major bends require bracket replacement.
Check for physical obstructions
Shine the torch along both tracks and across the lintel. Common blockers include broom handles, bikes, camping chairs, or tins of paint left too close. In winter, the bottom seal can freeze to the concrete; slip a plastic putty knife under the rubber to free it without tearing.
Do a balance test
Pull the red manual-release cord and lift the door halfway. A healthy system will hover or drift gently. If it slams down or shoots up, spring tension is off and further operation risks more damage—time to phone a pro.
Step 6 – Check Opener Settings, Gears, and Drive System
The electronics may be talking and the door hardware may be sound, yet the garage door not opening saga can still continue if the motor’s internal settings or drive train are out of whack. At this stage you’re dealing with low-voltage circuits and exposed sprockets rather than high-tension springs, so an attentive DIYer can usually investigate safely with the power isolated.
Before touching any screws, grab your manual (PDFs are often on the manufacturer’s site) and note where the travel and force dials are. Take a quick photo of their factory positions in case you need to roll back.
Adjust travel and force limits
Every opener needs to know two things: how far to move the door and how much push is acceptable. On Merlin CM128 and many Chamberlain models you’ll find two Phillips-head adjusters marked “UP/–” and “DOWN/+”.
- Turn clockwise for more travel; a quarter-turn equals roughly 50 mm of extra movement.
- If the force dial is cranked too high the logic board can interpret the extra load as an obstruction and shut down mid-lift.
Make small tweaks, re-engage the opener, and test. When the door stops consistently at both ends without straining, you’ve nailed it.
Inspect chain, belt, or screw-drive components
Remove the light cover and look along the rail. You want a firm but not taut chain or belt—no more than 25 mm sag halfway along the span. Cracked rubber teeth, missing chain links, or a stripped nylon coupler will cause motion without lift.
| Symptom | Likely Drive Issue |
|---|---|
| Chain/belt moves, door static | Trolley disengaged or broken |
| Loud clatter, jerky movement | Loose chain or worn sprocket |
| Motor hums, nothing moves | Stripped screw coupler |
Realign a slack chain with the tension bolt at the trolley; replace broken parts rather than bodging them with extra grease.
Reset or power-cycle the opener logic board
Glitches happen. Perform a soft reset by holding the “Program” or “Learn” button for six seconds until the LED goes solid. Still no joy? Unplug the unit (or isolate at the breaker) for a full 60 seconds before restoring power. According to the PAA snippet, many openers clear memory after a hard power loss unless they have battery back-up, so you may need to re-programme remotes afterwards.
If, after these checks, the motor stalls or gear teeth rain down like confetti, the internal gearbox has likely failed—time to book a technician rather than burn another Saturday.
Step 7 – Use the Manual Release and Test Door Function
If every powered check has drawn a blank, isolate the variable: remove the opener from the equation. Pulling the emergency release decouples motor and door so you can feel exactly what the panels, springs, and tracks are doing on their own.
How to safely pull the emergency cord
- Switch the opener off at the wall or breaker.
- Set a locked-out A-frame ladder under the rail and climb just high enough to reach the red handle.
- Stand to the side of the travel path, grip the handle firmly, and tug straight down until it clicks; never pull toward the door or you may snap the trolley.
Lift and lower the door manually
With the cord released, lift the door to waist height, then chest height.
- Smooth, balanced movement = the hardware is fine and the opener needs attention.
- Heavy, jerky, or drifting motion = spring tension, cables, or tracks are faulty and require a technician.
Re-engage by guiding the door along the rail until the trolley snaps back in place.
Step 8 – Decide Whether to DIY or Call a Professional
By now you know where the fault lives. The final question is whether it’s sensible—and safe—to tackle the repair yourself or hand it over. Use the quick litmus tests below.
Repairs within a capable DIYer’s reach
- Wiping and realigning photo-eyes
- Re-programming remotes, keypads, and travel limits
- Swapping a remote battery or wall-console face-plate
- Nipping up a loose track bracket or gently straightening a light bend
- Lubricating hinges, rollers, and springs with the correct spray
Jobs that should be left to the pros
- Spring or lift-cable replacement
- Opener motor, capacitor, or gearbox swaps
- Structural track repairs or panel replacement
- Any fault that leaves the door crooked, hanging, or over 30 kg unbalanced
Finding a trusted technician in NZ
Look for Worksafe registration, Site Safe membership, and at least $2 million public liability insurance. Expect:
- Call-out $90–$120
- Labour $80–$110 per hour
- Parts at trade plus 10–20 %
Ask for a written quote before work starts and check reviews on Trade Me Services or Google Maps.
Step 9 – Prevent Future Breakdowns with Simple Maintenance
Spending just one minute a month on basic upkeep saves hours of frustration and costly call-outs later. The following micro-tasks keep everything humming.
Monthly visual and functional checklist
- Listen for grinding or jerky travel
- Block the beam to test auto-reverse
- Check cables, rollers, and bottom seal
- Brush dirt from tracks and brackets
Lubricate moving parts every 6–12 months
Every six months mist hinges, rollers, and spring coils with lithium grease; use silicone on nylon belts, never on tracks.
Protect electronics and remotes
Fit a surge-protected plug and stash fresh CR2032s. Swap remote batteries every two years before they die.
Get Your Garage Door Back on Track
A door that refuses to budge is usually shouting about something simple. Work through the checklist in order: confirm power, unlock every switch or slide-bolt, pop a fresh battery into the remote, then march down the flow-chart—sensors, mechanics, opener settings, and finally the manual-balance test. Each stage rules out another suspect, so you’re never guessing in the dark.
Remember, if you spot a broken spring or sagging cable, back away and call a qualified tech; no saving is worth a shattered wrist. For everything else, a torche, a screwdriver, and a dab of lithium grease are often all the kit you need.
Door sorted? Keep it that way with a monthly glance and a six-monthly lube. And when the time comes for a new roller door, opener, or spare remote, check out DoorsNZ for quality, Kiwi-made gear shipped nationwide.