Troubleshooting
Garage Door Reverses Before or After Hitting the Floor: Why and the Fix
By HUSH Garage Door Service· Updated
A garage door that reverses before it reaches the floor has a blocked photo eye or close force set too low. One that reverses after touching down has the close limit set too far, so it keeps driving into the floor. Both are misadjusted safety features.
Do this, in order
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Watch where the door reverses
Run the door and note the exact point it backs up. Reversing before the floor points to the sensors or close force. Reversing after touching the floor points to the close limit. This single observation tells you which adjustment to make.
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Check the photo-eye sensors
Look at the two sensors near the floor on each side. Both indicator lights should glow steady. A flickering or off light means they are misaligned, blocked by a cobweb, or knocked out of position. Wipe the lenses and align them until steady.
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Clear the threshold
Sweep away ice, leaves, a stray bin, or debris under the door. The opener treats anything in the path as an obstruction and reverses to protect it, exactly as UL 325 requires.
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Locate the force and limit dials
Find the close limit adjustment on the opener motor head. On a LiftMaster or Chamberlain it is a small dial or button, usually behind a light cover, next to the close force setting. Check your model manual for the exact location. Leave the force alone: turning it up weakens the auto-reverse, so force adjustment is technician work.
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Make small adjustments
Shorten the close limit slightly if it reverses after touching down, moving in tiny increments, a quarter turn at a time. If it reverses before the floor with no obstruction, do not turn the close force up, because that weakens the auto-reverse. Have the sensors, track and balance checked, and leave any force adjustment to a technician.
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Run the safety reverse test
Place a 2x4 flat on the floor under the door and close it. The door must touch the wood and reverse immediately. Then close on nothing and confirm it seals without bouncing back. Readjust the close limit if it bounces back, and if it ever fails to reverse off the 2x4, stop using the opener and book a technician.
Stuck, or the door is under spring tension? Stop and call (343) 700-1077.
Why does my garage door reverse instead of staying shut?
Your garage door reverses because its auto-reverse safety system is doing its job, just at the wrong moment. A door that backs up before reaching the floor is reading a sensor block or too little close force. A door that backs up after touching down has its close limit set too far.
This behaviour is almost never a broken door. It is a safety feature, mandated by the UL 325 standard, that reads the wrong cue. The opener watches two things. The safety sensor beam across the bottom of the opening, and the motor’s close force, which is how hard it pushes before deciding it has hit something.
Set either incorrectly, or block the beam, and a healthy door reverses. The first diagnostic step is simply watching where the door reverses, because before-the-floor and after-the-floor point to opposite causes.
| Where it reverses | Usual cause | First thing to do |
|---|---|---|
| Part way down, well clear of the floor | The photo-eye beam is broken | Wipe both lenses, check for sun glare, nudge the brackets |
| Just as it touches the floor | Close force too low, or a stiff bottom seal | From fully closed, look at the springs, check balance by hand, and leave the force to a technician |
| Only on cold mornings | Thick grease and a stiff seal | Book a re-balance, and do not turn the force up yourself |
| At the same spot every time | A worn roller or a dented track | Book it, and do not raise the force to mask it |
Why does my garage door reverse before it reaches the floor?
If the door starts down, then climbs back up before it touches the floor, the opener thinks it hit an obstruction. The three usual culprits are misaligned photo-eye sensors, real debris in the path, or a close force set too low to overcome normal travel resistance.
Misaligned or blocked safety sensors
The two safety sensors, also called photo-eyes, sit about six inches off the floor on each side of the door. They project an invisible beam across the opening. Break that beam and the door will not close, or it reverses mid-travel.
Both sensor lights should glow steady. A flickering light, a cobweb across the lens, a bumped bracket, or sun glare hitting the receiver all break the beam.
Wipe both lenses and nudge the brackets until the lights hold steady. If they keep dropping out, the wiring or the photo-eye itself may have failed, which is covered under garage door opener and sensor repair.
An obstruction, ice, or debris on the threshold
The opener cannot tell the difference between a child’s foot and a frozen chunk of slush. A bin pushed too close, a garden hose, leaves piled at the threshold, or a ridge of ice all read as an obstruction.
The door touches it, senses resistance, and reverses exactly as designed. Sweep the threshold clean, clear any ice, and try again.
In Ottawa winters this is one of the most frequent reasons a perfectly good door starts reversing.
Close force set too low (catches normal resistance)
Every opener has a close force setting, often a dial or button on the motor head marked force or sensitivity. It tells the opener how much push is normal before it should assume it hit something.
If that force is set too low, the door’s own weight and roller friction trip it, and it reverses with nothing in the way. Check the balance first, but only once the door is fully closed, because a reversing door often ends up open and the release cord is never safe on an open door. If it will not stay down, hold the wall button until it closes, watching it the whole way with nobody under it, and if that fails, leave it, lock the door into the house and call. Once it is closed, look at the springs and cables without touching them, and if both look whole, pull the red release cord and lift the door by hand, since a door that binds will trip the force setting no matter how it is dialled in.
If it lifts easily and stays put where you leave it, lower it back to the floor and leave the close force alone. Turning it up weakens the auto-reverse that stops the door on a child or a car, so a door that still reverses needs its sensors and track checked, and any force adjustment made by a technician.
If you are unsure which fault the opener is reporting, see the blinking opener light codes explained guide, since many openers flash the photo-eye and force faults the same way.
How does the LiftMaster safety reversing sensor make the door reverse?
The LiftMaster safety reversing sensor is the pair of photo eyes LiftMaster calls The Protector System, and a broken beam sends a closing door back up. Each eye has a light: the sending eye glows amber and the receiving eye glows green, and a green light that flickers or goes out means the beam is blocked or misaligned.
LiftMaster mounts the eyes no more than 6 inches above the floor, facing each other across the opening. When the beam is broken, the opener will not close from a remote or keypad, and the main opener light flashes to flag the sensor fault.
On older LiftMaster openers, holding the wall control button down until the door is fully closed overrides the sensors for that one close, so watch the whole way with nobody under the door. Chamberlain Group removed that override from openers and replacement logic boards made after February 3, 2022, so a newer unit will not close at all until the beam is clear. The override gets you through a night; it is not a fix. Clean the lenses, square the brackets until the green light holds steady, and if it still drops out, the eye or its wiring has failed.
Why does my garage door reverse after it touches the floor?
If the door reaches the floor, briefly seals, then opens back up, the cause is the opposite end of the system. Now the opener is overshooting or miscounting travel, so the three usual culprits are a close limit set too far, worn rollers adding drag, or a seal binding on the slab. It is the fault people describe as a garage door that bounces when closing.
Close limit set too far (the door drives into the floor)
The close limit tells the opener exactly how far to travel before the door is fully shut. Set it too far and the opener keeps driving after the door is already on the slab, so it reads that push as hitting an object and reverses. Find the close-limit adjustment, usually a separate dial or up-down button from the force, and decrease the down travel slightly so the door just meets the floor with no extra strain. Chamberlain gives the same fix for a door that hits the floor and reverses. Move in small steps and retest after each change. On a Genie SilentMax 1000, model 3042, that starts reversing right after a power outage, unplug it for 30 seconds first, then follow the limit-setting steps in Genie’s manual for that model if the reverse survives the reset.
Worn rollers or a binding track adding drag
If the rollers are dry, cracked, or worn flat, the door drags as it nears the floor. That extra friction reads to the opener as resistance, and it reverses.
The same happens when a track is dented, loose, or out of plumb so the door binds in the last foot of travel. Fresh nylon rollers and a properly aligned, clean track remove that drag. A garage door tune-up and safety inspection replaces tired rollers and re-times the limits in one visit.
A failing weather seal freezing to the slab
The bottom weather seal is rubber, and cold rubber gets stiff. A hardened or cracked seal grabs the concrete instead of compressing softly against it.
The opener feels that grab as an obstruction the instant the door lands, and reverses. In freezing weather the seal can also bond to the slab outright. Replacing a brittle bottom seal and keeping a silicone lubricant on it lets the door seat cleanly without tripping the reverse.
Why does the door reverse more below -20 C in Ottawa?
Reversing is a classic Ottawa and Gatineau winter call because cold adds drag everywhere the opener measures it. Stiff lubricant, hardened rollers, a frozen bottom seal, and ice on the threshold all increase resistance, and the opener reads that resistance as an obstruction.
When the temperature drops below freezing, the factory grease in the rollers and hinges thickens and the rubber seal loses its flex, so the whole system takes more force to move. A close force that worked fine in October is suddenly too sensitive in January, so the door that closed all autumn starts reversing.
This is why we often just re-balance the door and bump the close force slightly during a winter visit, rather than replacing parts.
If your door reverses only on the coldest mornings and behaves the rest of the year, cold-weather drag is the most likely answer. A door that won’t close at all in the cold is a related but separate problem worth ruling out.
Should I turn the auto-reverse off to stop the door reversing?
No. Never disable the auto-reverse. It is the entrapment protection defined by UL 325, the standard every major opener sold in Ottawa is built to.
Its job is to stop a closing door crushing a child, a pet, or the back of a car. Switching it off strips the door of the only system that will stop it.
Some homeowners try to defeat the reverse by cranking the close force to maximum or bypassing the sensors. Both are unsafe and both hide the real fault instead of fixing it. The right move is always to find why the door reverses and correct the sensor, force, limit, or hardware that is tripping it. If the door reverses with the sensors clearly aligned and the path clear, the cause is mechanical or electronic, and that is a job for opener and photo-eye repair, not a workaround.
How does a technician set the auto-reverse force and limits correctly?
A technician works in 4 steps. Set the balance. Dial the close limit so the door just reaches the floor.
Raise the close force only as far as it needs. Then confirm the door reverses off a 2x4. Balance before force is the rule.
Force is set last because if the door is out of balance, the spring is fighting the opener, and no force setting will be both safe and reliable. So the spring tension and door balance get checked first by lifting the door by hand to mid-travel and seeing if it holds.
Only then are the limits and force tuned. The final safety reverse test, laying a flat 2x4 under the door and confirming it touches and reverses, is the proof the settings are correct. We run that test on every opener we service, and walk you through it so you can repeat it yourself.
How much does setting the force and limits cost in Ottawa?
A reversing-door fix starts at a service call, free when the repair runs over $250. Our service call starts at $150, and it is free when the repair runs over $250. A pure force and limit adjustment is often handled inside that visit. Opener and sensor repair starts from $185 if a part has failed.
Most reversing problems are an alignment, a clean threshold, or a dial adjustment, so they fall at the low end. If a photo-eye, a roller set, or the opener logic board has actually failed, the repair starts from $185, with new nylon rollers from $100 a set. There are no overtime or weekend surcharges. We carry common LiftMaster, Chamberlain, and Genie sensors and parts on the truck, so most reversing calls are solved on the first visit with same-day emergency repair in Ottawa.
When should a technician set the force and limits instead of you?
Call a factory-trained technician on any of three signs. The sensors are aligned and the threshold clear, and it still reverses. You suspect a worn roller or a binding track.
Or adjusting the close limit will not hold. These point to a mechanical or logic-board fault, not a setting.
A door that reverses with no obstruction and steady sensor lights has usually moved past the DIY stage. It could be a failing photo-eye, an intermittent logic board, a roller dragging only under load, or spring tension that has drifted out of balance. Our factory-trained technicians test the real force draw on the motor, check the balance by hand, and inspect the rollers and track.
The fix then targets the cause instead of masking it. For the wider picture of opener and door faults, start with our full garage door troubleshooting guide. Then call us at (343) 700-1077.