Emergency Garage Door Repair
Fast attention for doors hanging crooked, jammed part-way, or stuck wide open.
View serviceGarage Door Will Not Close: How to Diagnose It Step by Step
A door that opens fine but refuses to close is usually protecting you from something. Work through the cheap causes in order before touching a single adjustment screw on the opener.
Short answer
Clear everything from the threshold, including packed snow and ice. Wipe both photo eye lenses and check the small indicator lights are steady rather than flickering. Look along the tracks for anything jammed and along the cables for slack. If the door still refuses, pull the manual release and try closing it by hand: if it moves smoothly the fault is in the opener or its sensors, and if it binds or feels heavy the fault is in the door and should be left to a technician.
A garage door that will not close is one of the most common calls of the year, and it is also the fault most often solved in five minutes without tools. Modern openers are built to refuse to close whenever anything suggests the path is not clear, so the first question is never what is broken but what the opener thinks it is seeing. The candidates, roughly in order of how often they are responsible, are an obstruction at the threshold, a photo eye that is dirty, knocked or wired badly, a close limit set wrong, friction in the door that the opener reads as an obstruction, and a genuine mechanical fault in the track, rollers or cables. Working through them in that order costs nothing and avoids the classic mistake of turning up the close force, which does not fix the cause and removes the protection that was working correctly.
Diagnose in order
Work Through These Checks
Start at the top. The early checks are the most common causes and need no tools.
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Clear the whole threshold
Move bins, tools, bicycles, salt bags and floor mats away from the opening, then look along the entire line where the seal meets the concrete, including both corners where snow and grit pack in. In a Hamilton winter a ridge of frozen slush is enough. Then run one closing attempt from a safe position and note whether the door stops at the same height as before.
What it means: A clean close after clearing the floor means the obstruction was at the threshold, not in the opener.
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Clean and align the photo eyes
The two sensors face each other low on the jambs. Wipe both lenses with a dry cloth, check nothing is stored in the beam and confirm the brackets are still square rather than knocked. Most units show a steady light when aligned and a flickering or absent one when not. Follow the wiring up the jamb looking for staples through the insulation or damage from damp.
What it means: If the door closes once the eyes are clean and aligned, the safety circuit was doing exactly what it should.
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Read the opener's own diagnostics
Most openers made in the last twenty years flash a code with the light or a small LED on the head unit to indicate a sensor fault, a limit problem or a force trip. The label inside the cover or the manual tells you which is which. Note the pattern before you change anything, because it usually points straight at the subsystem responsible.
What it means: A sensor code sends you back to the photo eyes; a force or limit code points at the door itself.
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Test the door by hand
With the door open, pull the manual release cord to disconnect the trolley, then lower the door by hand. It should travel smoothly, without grabbing, and sit down evenly across the whole width. If it binds at a particular point, or feels heavy enough to be a struggle, stop and leave it down.
What it means: A door that binds or feels heavy by hand has a mechanical fault, and the opener is only the messenger.
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Look at the tracks, rollers and cables
Sight along both vertical tracks for dents or a section pulled off the jamb, check the rollers are all sitting in the track, and look at both cables for slack, kinks or fraying near the bottom. Also check the top section around the opener arm bracket for cracking. Do not touch the bottom brackets or any spring hardware.
What it means: Slack cable, a roller out of track or a cracked top section means stop using the door and book a repair.
Where to stop
Know the Limit
There are three things not to do here. Do not increase the close force to make the door stop reversing, because that is the setting that decides whether the door stops when it hits something. Do not raise, bypass or tape over the photo eyes, for the same reason. And do not force a door down by hand if it feels heavy, because a heavy door means the counterbalance is compromised and the door can drop. If a cable is slack or a spring shows a gap, keep the door down, keep the opener off and keep everyone out of the opening until it has been looked at.
Local conditions
Why It Happens Here
Winter does most of this in Hamilton. With around 40.8 centimetres of snowfall in January alone at the airport station and 66.4 freeze-thaw days a year, a thaw followed by a freeze leaves a ridge of ice along the threshold that a door cannot seat against, and the opener correctly reads it as an obstruction. Escarpment-side streets add grade, so meltwater running down a sloping driveway collects exactly at the door line. Snow pushed up against the jambs by a plough or a blower also buries the photo eyes, which is why clearing the threshold and the sensor brackets is the first thing to try rather than the last.
Questions
Common Questions
Why does my door start closing then go back up?
Something is telling the opener the path is not clear. Most often it is the photo eyes, whether from a dirty lens, a knocked bracket, damaged wiring or an object stored in the beam. Next most often it is friction in the door tripping the close force, typically at the threshold or at a seized roller. The reversal itself is the safety system working, so the fix is to remove the cause rather than to reduce the sensitivity.
Can I close the door manually and leave it until it is repaired?
Yes, provided it moves smoothly and feels normally light. Pull the manual release, lower it by hand, and leave the opener unplugged so nobody runs it against the fault. If the door feels heavy or wants to run down on its own, do not put yourself under it; leave it where it is and keep the opening clear until a technician has secured it.
The lights on my opener are flashing. Does that mean it is broken?
Usually the opposite: it means it is reporting a fault it has detected, most commonly in the photo eye circuit. Count the flashes and compare them with the label on the unit or the manual, because the code will tell you whether to look at the sensors, the limits or the force settings. It is the cheapest diagnostic information available and it is often ignored.
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Where We Work
These guides are written for Hamilton homes. If the fix is beyond a homeowner check, we work everywhere inside this area.
Map data © Google. Pin shows the service area, not a walk-in location — all work is done at your home.
From the tools
A real callout, not stock imagery.
A sectional door pulled off its tracks, taken down and supported on site so it could be checked and re-hung safely — photographed on the job.