A blinking LiftMaster light is a diagnostic code. Count the flashes of the LED beside the Learn button, or the Up and Down arrow flashes on myQ models, then match them to your model's chart. Most codes point to the safety sensors: a loose or reversed wire, or sensors out of line. Five or six flashes point to the motor side, which needs a technician.
Quick answers
What do the blinking lights on a LiftMaster garage door opener mean?
They report a fault. Count the flashes of the LED next to the Learn button, or the Up and Down arrow flashes, and match them to the chart for your model. Most codes point to the safety sensors.
Why does my LiftMaster light blink and the door will not close?
The most common cause is the safety reversing sensors: misaligned, blocked, in sunlight or with a damaged wire. The maker lists these causes for the 10-flash bulb warning.
How do I fix the sensors on a LiftMaster opener?
Clear the beam, loosen the wing nut, aim the sensors at each other until both LEDs glow steadily, tighten and test. If it still fails, check the wire.
What does it mean when the wall control flashes?
The lights flashing twice means the LOCK button is on and the remotes are locked out. Press LOCK to turn it off.
The full explanation
What the blinking means
Your opener has a built-in self-test. When it finds a fault, it reports it with a pattern of flashes. On many LiftMaster openers the LED next to the Learn button flashes a set number of times, pauses, then repeats. On myQ openers with Up and Down arrows, the arrows flash instead, so one Up flash plus one Down flash is code 1-1.
The model number is on a label on the side or back of the motor unit. It decides which chart applies, because jackshaft openers and some DC models have their own charts. The table below covers the common AC-powered chart and the arrow codes for sensor faults.
Blink codes and what they usually mean
| Signal | What it means | Where to look |
|---|---|---|
| 1 flash | Broken or disconnected wire to a safety reversing sensor | Wire at each sensor and at the opener |
| 2 flashes | Sensor wire shorted, or the black and white wires are reversed | Pinched or crushed wire, wrong terminal |
| 3 flashes | The LED or screen on the door control is not lit | Door control and its wire |
| 4 flashes | Sending sensor LED steady, receiving sensor LED dim or flashing | Sensor alignment, sunlight |
| 5 flashes | No motor rotation detected in the first second | A stuck or heavy door: stop and call |
| 6 flashes | Motor circuit failure, usually a logic board replacement | Technician job |
| Arrows 1-1 | Sensor wires cut or not connected | Same as 1 flash |
| Arrows 1-2 | Sensor wires reversed or shorted | Same as 2 flashes |
| Arrows 1-4 | Sensors misaligned or briefly blocked | Same as 4 flashes |
Charts differ by model. Confirm the code against the chart for your model number in the sources below.
Light bulbs flash 10 times, or twice
If the door will not close and the opener's light bulbs flash 10 times, the maker says the safety reversing sensors are the cause: misaligned, blocked, hit by sunlight or wired badly. The 10-flash warning is not on openers and logic boards made after 2022, so use the LED or arrow code on those.
If the lights flash twice, the LOCK button on the door control is on. The wall control still works, but the remotes are locked out. Press LOCK once to turn it off, then try a remote.
Five checks, in order
Read the code
Count the flashes more than once and write the number down. Find the model number on the motor unit label.
Clear the beam
Each sensor sits on a track no more than 6 inches above the floor. Move anything blocking the path between them and wipe both lenses.
Realign the sensors
Loosen the wing nut and aim the sensors at each other until both LEDs glow steadily. Tighten the wing nut and test.
Look for sunlight
Strong sun on the receiving sensor (green LED) can blind the sending sensor (amber LED). Shade the lens and test again.
Inspect the wire
Follow each sensor wire to the opener and look for a pinched, cut or loose section. A damaged wire is a replacement job.
Do not disable the sensors
Since 1993, openers have had to include entrapment protection, such as an electric eye, according to the U.S. Consumer Product Safety Commission. Do not unplug, tape over or hold the sensors out of the way to get the door closed. A door that needs that is a door that needs a technician.
Five flashes can mean the door itself is stuck or very heavy. Do not lift against the opener, and never adjust a spring or cable. Those are under high tension and are a technician job. See spring repair.
When the code is not a sensor problem
Codes 5 and 6 point away from the sensors. A heavy, crooked or off-track door can stall the motor, and a failed motor circuit needs the logic board replaced. For a sensor that stays dead after cleaning and realigning, or a damaged wire, sensor work falls in our $150 to $350 range for rollers, sensors or a tune-up, and the final price is confirmed after we see the door. More on sensors: why the sensor light blinks and why a door will not close.
Get the code read
Emil Garage Doors repairs LiftMaster and other openers across Southern California, for example in Woodland, Newport Beach and Brawley. Call (213) 340-4232 with the flash count and the model number, or use the estimate form, and we will tell you what the repair involves. See opener repair.
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Read next
Sources
- Chamberlain Group support: What does the flashing LED next to the Learn button mean
- Chamberlain Group support: Why do the lights on my garage door opener flash and my door will not close
- Chamberlain Group support: Diagnostic codes for garage door openers (which chart fits which model)
- U.S. Consumer Product Safety Commission, Safety Commission Publishes Final Rules For Automatic Garage Door Openers