Why Won't My Garage Door Close? 7 Things to Check First

A garage door that opens normally but refuses to close is one of the most common calls we get across the GTA. The good news: it is usually not the opener, and several of the causes take about two minutes to check yourself before you call anyone.

1. Something is blocking the safety sensors

Every garage door built since the early 1990s has two photo-eye sensors, one on each side of the door about six inches off the floor. They shine an invisible beam between them. If anything breaks that beam, the door refuses to close — it will start down, then reverse and go back up. This is a safety feature working exactly as designed.

Look for a bin, a bike wheel, a broom, a coiled hose or a pile of leaves sitting in the beam's path. Move it and try again.

2. The sensors are misaligned

The brackets holding the sensors are thin and easily knocked. A bumped bracket, a bag brushing past, even vibration over time can twist one a few degrees out of line. Check the small LED on each sensor: both should be lit and steady. A light that is off, flickering, or a different colour than its partner means they are not seeing each other. Gently adjust the sensor until both lights go solid.

3. The sensor lenses are dirty or sun-blinded

Dust, cobwebs, road salt and condensation on the lens will break the beam just as well as a physical object. Wipe both lenses with a dry cloth. Direct low sun hitting a lens can also overwhelm it, which is why some doors mysteriously refuse to close only in the late afternoon.

4. The close-limit setting has drifted

The opener has a setting telling it how far to travel before the door is fully closed. If that limit drifts, the opener thinks it has hit the floor early, assumes it has struck an obstruction, and reverses. The tell-tale sign is a door that closes all the way, touches down, and then immediately opens again. This is adjustable on the opener, but getting it wrong leaves a door that either will not seal or slams into the floor.

5. The track is obstructed or bent

Run your eye up both vertical tracks. A dent, a bulge, or a bolt that has worked loose will stop a roller from passing. In winter, ice built up along the bottom seal or frozen to the floor will also stop the door and trigger the reverse.

6. The remote or wall button is stuck

A wall button jammed in the pressed position, or a remote with a stuck button in a coat pocket, holds the opener in a state where it will not complete a close cycle. Unplug the opener for thirty seconds and plug it back in. If the door then closes from the wall button but not the remote, you have narrowed it to the remote.

7. A broken spring or cable

If the door also feels unusually heavy, sits crooked, or you heard a bang recently, the problem is mechanical rather than electronic. A door with a broken spring may still open under opener power but will not travel properly, and forcing it will damage the opener. Stop using it and get it looked at — this is not a DIY repair.

When to stop and call someone

Checking sensors, clearing obstructions and wiping lenses are all safe. Adjusting spring tension, straightening tracks under load, or working on cables is not — those components hold hundreds of pounds of stored energy.

Modern Empire Doors has served the Greater Toronto Area since 2018 and answers the phone 24 hours a day, 7 days a week. We cover Richmond Hill, Vaughan, Markham, Toronto, Aurora, Newmarket, King City, Thornhill and Durham. Call 647-323-1826.