The door starts down like normal. It gets a foot, maybe three feet, maybe all the way to the concrete, then it stops, changes its mind, and goes back up. Nothing is bent, nothing is broken, and it will do it again as many times as you ask.
This is the most common call we take that is not a snapped spring, and the one people apologise for. "It is probably nothing, it just will not close." It is not nothing, but it is usually cheap, and you can narrow it to one of four causes before calling anybody.
The door is not malfunctioning. It is refusing.
Every opener built since 1993 is required by federal law to reverse rather than crush something, and the law exists for the reason you would guess. So it carries two independent ways of deciding the way down is not clear, and either one sends the door back up.
The first is the pair of photo eyes: the small sensors bolted to the track about six inches off the floor, with an invisible beam running between them. Break that beam while the door is closing and it reverses. There is no debate and no override.
The second is force. The opener has learned roughly how much effort closing this door should take, and if it meets more than that before reaching the point it calls "closed", it assumes it has landed on something. A door that goes back up is not ignoring you, it is reporting an objection, and it is right more often than people expect.
How far it gets before it comes back is the diagnosis
Close the door, watch it, and note where it gives up. Three times, because the difference between "always" and "sometimes" is half the answer.
- A few inches, then straight back up. Almost always the photo eyes. The beam is broken before the door has done anything at all.
- The same height every single time. Something physical is in the way at that point: a bent section of track, a roller out of its groove, a hinge catching. The repeatability is the clue.
- A different height each time. That points at friction rather than an obstruction, dry rollers, a gritty track, a door that has quietly got heavier at the motor.
- It touches the floor and bounces back up. The down limit or the down force is set wrong. The door has arrived and the opener does not believe it.
Four behaviours, four different jobs. Most people skip this and start cleaning the sensors, which is the right fix about a third of the time.
The photo eyes are usually working and usually aimed wrong
Both sensors carry an indicator light. One sends, one receives, and the rule is simple: two steady lights means the beam is good. A flickering or dark receiver light means it has lost sight of its partner.
What knocks them out of line is rarely dramatic. A bike leaned against the bracket. A vacuum hose. Several thousand cycles slowly nodding a bracket downward over a year. We have found a spider web dense enough to break the beam, and a receiver blinded for twenty minutes every afternoon because the low September sun comes straight up the driveway into the lens. That last one presents as an intermittent electrical fault and is a sun angle: if your door only refuses to close between five and six, you do not have a wiring problem.
Wipe both lenses, loosen the wing nut, aim one squarely at the other until the receiver light goes solid, and tighten it. That is the entire repair and it costs nothing.
Walk the opening before you look at the opener
An obstruction does not have to be large, or in the middle where you would notice it. The door only has to meet it.
- The bottom seal, curled, hardened or torn, it hangs lower at one end and catches on the way past.
- A recycling bin, a hose reel, a bag of potting soil parked just inside the line of the door, in the six inches nobody looks at.
- A stone in the track channel at floor level. It takes exactly one.
We charge a call-out fee to drive across town and move a bag of soil. Nobody enjoys that conversation, and it takes ninety seconds to rule out yourself.
When it reaches the floor and bounces back up
This gets misdiagnosed as a sensor fault more than anything else on the list. Two settings have to agree: the position the opener calls "closed", and the force it expects to have used getting there. If the limit sits slightly too low, the door meets concrete before the opener thinks it has arrived, reads that as an obstruction and backs off.
Both are adjustable at the motor head and both are easy to make worse. A down force wound up high enough to make the symptom disappear is a door that will keep pressing on whatever is underneath it, precisely the event the reversal exists to prevent. Limit first, force second, then prove it against a solid object on the floor rather than your hand.
Why it started doing this when nothing changed
Almost nobody calls the day after something new arrives in the garage. They call after two years of a door that worked perfectly, which makes the fault feel arbitrary. It is not. Springs lose tension gradually, rollers dry out, and dust off a dry driveway works into open bearings all summer. None of that is enough to stop a door, only enough to push it past a force threshold set when everything was new, which makes an intermittent reversal the first honest symptom of a door due a service.
What actually happens when we come out
The order matters more than the parts do:
- Pull the release cord and lift the door by hand. A balanced door moves with two fingers and stays where it is left. If it fights back, the problem is the spring, and adjusting the opener would only hide it.
- Check both sensor lights, the alignment, and the low-voltage wire back to the motor head. A staple driven through that wire during a remodel stays intermittent for years.
- Set the down limit, then the down force, then prove the reversal on the floor.
Half of these visits end with clean lenses, a straightened bracket and a limit adjustment. We would rather talk somebody through that on the phone and lose the call than drive out for it.
The short version
Watch where it stops. A few inches means the beam. The same spot every time means something physical. A different spot every time means friction. The floor itself means the limit or the force.
Clean the lenses, square up the brackets, walk the opening. If it still comes back up, the door is telling you something true about its condition, and it is cheaper to listen now than after the spring makes the same point.
Garage Door Doctor’Z · (833) 991-3899 · doctorzgaragedoor.com
CSLB C61/D28 · Lic. 1138150 · Serving the Sacramento Valley since 2018.
