A garage door that goes down and then back up is usually reacting to its safety sensors. The beam is blocked, dirty or knocked out of line. If the sensors are fine, the cause is often the limit settings, a door that drags in its track, or the logic board. Most sensor problems take a few minutes to check at home.
The short answer
When your garage door goes down and then goes right back up, the opener thinks something is in the way. Most of the time it is the safety sensors. Sometimes it is the door itself, or the opener's limit settings.
This is one of the most common opener calls in New Westminster. It is also one of the easier ones to narrow down yourself.
How the reversing system works
Two small sensors sit on either side of the door, near the floor. They send an invisible beam across the opening. If something breaks the beam, the opener stops the door and sends it back up.
The opener also senses resistance. If the door meets something solid, or feels heavy and tight, it reverses. That protects people, pets and cars.
So a reversing door is the opener doing its job. The question is what it is reacting to.
Check the sensors first
Work through these checks in order. None of them need tools.
- Look at the small lights on each sensor. Both should be steady. A blinking or dark light means the beam is blocked or the sensors are out of line.
- Clear anything in the path of the beam. Bins, bikes, boxes and hanging items are common culprits.
- Wipe each sensor lens with a soft, dry cloth. Dust, damp and cobwebs can block the signal.
- Look at each sensor bracket. If one has been bumped, it may point slightly off. Gently nudge it back until the light goes steady.
- Check that the wire to each sensor is still attached and not pinched or chewed.
If the lights come on steady and the door closes properly, you found it.
A note for this week
Halloween is four days away. Pumpkins, fake cobwebs, string lights and cardboard decorations often end up near the garage door. If any of them sit across the sensor beam, the door will reverse.
Keep decorations clear of the sensors and the path of the door. Trick-or-treat night also means more foot traffic near driveways, so it helps to keep the door area tidy.
Damp, shaded lots make this worse
New Westminster is mild and wet in the fall. Many lots slope down toward the Fraser River and sit partly in shade, so things stay damp longer. Sensor lenses collect grime and moisture, and wood doors and frames swell and wear.
In Queensborough, the newer houses and townhouses have modern doors and openers. A reversing problem there is usually a sensor issue, since the door itself tends to run freely.
In Queen's Park and Sapperton, the older homes often have original single-car garages. Many have older doors, sometimes with extension-spring systems. A door that sticks or drags in its track feels heavy to the opener, and the opener reverses to protect itself. In that case, cleaning the sensors will not fix it.
When the sensors are fine
If both sensor lights are steady and the door still reverses, look at these causes.
The door is binding
Watch the door as it moves. Does it scrape, shudder or tilt to one side? Swollen wood, a bent track or worn rollers can all cause drag. Disconnect the opener with the red release cord, with the door closed, and lift the door by hand. It should move smoothly and stay put about halfway. If it feels heavy or jams, the problem is the door, not the opener.
The limit settings are off
The limit settings tell the opener where the floor is. If the close limit is set too far down, the door hits the floor and the opener reads it as an obstruction. This often shows up after a power cut, or after someone has adjusted the opener.
The logic board is failing
A worn logic board can send the door back up for no clear reason. It may work for days and then act up. If the opener also works sometimes and not others, the board is a likely suspect.
What not to do
Don't hold the wall button down to force the door closed and call it fixed. That bypasses the safety reversal on many openers, and it hides the real problem.
Don't disconnect or tape over the sensors. They are there to stop the door from closing on a person, a pet or a car.
Don't touch the springs or cables. On older doors with extension springs, a broken or stretched spring can cause injury. Leave those to a technician.
When to call a professional
Call if the sensors are clean, aligned and showing steady lights, and the door still reverses. Call if the door drags, tilts or makes grinding noises. Also call if the opener works only sometimes, or if you are unsure whether the problem is the opener or the door.
We check the whole door before touching the opener. Then we tell you plainly whether a repair makes sense or whether an older door is better replaced. You get a quote before any work starts. An opener repair usually takes about 1 to 2 hours.