Garage door opener troubleshooting: what to check before you call

Start by separating the door from the opener

Before diagnosing the opener at all, close the door, pull the red release cord and lift the door by hand. If it's heavy, binding, or won't stay where you leave it, the problem isn't the opener — it's the spring system, and the opener is just the thing complaining about it.

If the door glides smoothly by hand and holds at waist height, the door is fine and you can move on to the unit itself.

The motor hums but the door doesn't move

Reconnect the trolley and try again. If the motor runs with no movement, the usual causes are a stripped nylon gear inside the head, a failed starting capacitor, or a trolley that never re-engaged after someone pulled the release cord.

The trolley is the one you can check: run the opener until the carriage reaches the arm, then pull the door up by hand until it clicks back in. If the carriage travels the rail but the door stays still, it's internal — a gear kit or capacitor, both repairable.

The door closes a foot then reverses

This is the safety sensors nine times out of ten. Look at the two small units mounted six inches off the floor on each track. One should show a steady light, the other a steady light of a different colour. A blinking or dead light means they aren't seeing each other.

Check the obvious first: a bike, a bin, a coiled hose or a stack of boxes breaking the beam. Then check alignment — sensors get nudged constantly. Loosen the wing nut, aim one at the other, and tighten when both lights go steady.

If both lights are dead, it's a wiring fault. Staples through the sensor wire are the classic cause, and the break is usually where the wire runs along the track.

The door reverses immediately after touching the floor

That's the close-force or down-limit setting, not the sensors. The opener thinks it has hit an obstruction because it's still pushing after the door has landed. The down-limit screw or button on the opener head adjusts where it stops.

Be careful here. Too much close force disables the safety feature that stops a door on a child or a pet. If adjusting the limit doesn't fix it in one attempt, stop and get it checked.

Remotes and keypads have stopped working

If one remote is dead but the wall button works, it's the remote — usually the battery, occasionally lost programming after a power cut.

If every remote and the keypad are dead but the wall button works, the receiver logic board or its antenna is the issue. A snapped or coiled-up antenna wire hanging from the opener head cuts range dramatically.

If nothing works including the wall button, check the breaker and the outlet first. Garage outlets are often on a GFCI that has tripped somewhere else in the house.

When repairing stops being worth it

Under roughly twelve years old with a gear, capacitor, sensor or board fault: repair. Past that, parts availability thins out and you're paying to keep a unit alive that will fail again. A new belt-drive opener installed starts around $425, and the quiet difference from an old chain drive is significant.

Ask for both numbers — repair and replace — and decide with them in front of you.