Liftmaster garage door openers are built to last. But like any mechanical device, they can break down from time to time. When this happens, knowing how to troubleshoot and fix the problem can go a long way.
Thankfully, Liftmaster garage door openers have built-in self-diagnostic features that make it easier to identify and fix a problem when the opener breaks down. All you have to do is know what to look for.
This article walks you through the various Liftmaster flashing light codes to guide you when troubleshooting a problem. Read along to learn how to interpret and use these codes.
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Which Liftmaster flashing light codes are there?
LiftMaster garage door openers have three types of troubleshooting codes:
- A small indicator LED next to the opener’s Learn button. This light can be located on the down-facing side of the motor unit or the back panel.
- Up and Down arrow buttons on the side or back panels of the motor unit.
- The light bulbs on the motor unit blink ten times or repeatedly to signify a problem.
Your opener may use more than one code at a time to specify the problem. For instance, a blinking light bulb may be accompanied by a flashing LED indicator next to the unit’s Learn button.
If the light bulbs on the opener blink ten times, the sensors may be damaged or misaligned, or the sensor wires may be broken. In this case, studying the LED indicator will help narrow down the problem for you.
This article discusses these LiftMaster flashing light codes in sets below to make it easier for you to navigate.
Liftmaster opener Light flashes continuously
Your Liftmaster garage door opener comes with remotes that you can program not to open the door for security purposes. The remotes have a built-in lock feature that you can engage to prevent the device from opening and closing your garage door.
When this lock is engaged, the light bulbs on your opener will continuously flash if you attempt to open the door with the remote.
So if you see this code, your remote will not open the door. But you can still use the wall control button or manual keypad to operate your garage door.
How to resolve the issue
When you notice the opener flashing continuously, locate the lock button on your garage door remote and press and hold it down for about two seconds.
Doing this will disengage the lock and allow the remote control to resume opening and closing the garage door.
The motor unit flashes ten times
Your LiftMaster garage door opener will likely have a light bulb on each side. The two bulbs will blink simultaneously to send an error code when activated, producing single flashes through the cover.
When the unit flashes ten times, it usually symbolizes a security sensor problem. Modern garage door openers have two sensors installed on each side of the door to detect the presence of objects, people, and pets in the doorway and prevent accidents.
If these sensors are misaligned, damaged, blocked, or have a wiring problem, the garage door will not close, and the opener will blink ten times.
What to do when this happens
Since the blinking can mean one of four sensor-related problems, we recommend checking the LED indicator or up-down arrow buttons on your motor unit for a more specific diagnosis.
The LED or up-down arrows will blink a specific number of times, corresponding to a particular problem, as discussed below.
But first, inspect the sensors on both sides of the garage door for noticeable blockage or misalignment.
Note: Any garage door opener manufactured after 2022 will not have this feature. The same applies to any replacement logic board manufactured in late 2022 or after.
LED Next to the Learn button flashes 1, 2, or 4 times
Such a flashing LED indicates a safety sensor-related problem. The light will blink a specific number of times, stop, then start the cycle over again.
Here is the breakdown of the likely problems and the corresponding codes if your garage door opener is an older chain drive model.
- If the LED indicator blinks once, the security sensor wires are disconnected or broken.
- If the LED indicator blinks twice, the sensor wires are shorted or reversed.
- If the LED indicator blinks four times, the sensors are misaligned or blocked. One of the sensors (sending sensor) will have a steady amber glow, while the other sensor (receiving sensor) will have a dim or blinking green light.
How to fix the problem
Follow these steps to inspect your garage door sensor wires for a broken, disconnected, or shirted part.
- Start by removing the cables from behind the wall next to each sensor and visually inspect them for loose connections or damaged, broken parts. If you find any, replace the damaged cables or tighten the loose connection.
- Check the sensor wire terminals on the motor unit and gently pull each to see if any of them comes off. This should tell you if there is a loose connection or breakage in that area. If you find any, replace or reattach it accordingly.
- Check the terminals on the motor unit for shorted wires. The white wires should connect to the white terminals while the white wires with black stripes attach to the grey terminal.
- Realign any misaligned safety sensors by loosening the wing nut that attaches the misaligned sensor to its respective bracket. Gently move the sensor to realign it until the green light on the receiving sensor shines a solid green, then tighten back the wing nut.
- Each sensor should be six inches from the garage floor, so any sensor more or less than six inches from the ground is the culprit.
- Additionally, clean any lens with accumulated dirt that might block the sensor beam.
The LED indicator Next to the Learn button flashes three times
This typically indicates a problem with the garage door control. You will find that the screen or LED on the garage door control is not lit when the opener sends this code.
What to do
Check the cables on your door control. Inspect them for short or visible damage and replace the affected wire.
If you see no visible damage, test the cables by following the following procedure.
- Unscrew and pull the door control from the wall, then disconnect the cables from the back.
- Touch the wires together and observe what happens. If the garage door moves, your door control is faulty; replace it.
- If nothing happens, the door control is probably okay. Remove the door control wires from the white and red terminals on the motor unit and connect each end of a 3-inch jumper wire to each terminal. If the door moves, replace the door control cables; they are the problem.
The LED indicator Next to the Learn button flashes five times
This code indicates a mechanical stoppage problem preventing the opener from detecting any RPMs in the first second of garage door operation.
What to do
How you approach fixing this problem depends on the following additional indicators.
- Unplug the opener’s power cable from the outlet for five seconds before plugging it back if the unit is operating normally.
- Check if the garage door is balanced if the opener turns off after humming for 5 seconds or longer. You will need to pull the emergency release cord and lift the door halfway with your hands. If it feels heavy to lift or falls shut by itself, have a technician check it.
The LED indicator Next to the Learn button flashes six times
This happens when the circuit board in a motor unit has a failure.
What to do
If this happens, replace the logic board in the unit. You may need to have a technician do this for you.
Up-Down Adjustment Arrows
Some LiftMaster garage door openers have up-down arrows that blink in specific patterns to send error codes. Once you understand the blinking patterns corresponding to the various error codes, you can use them to diagnose and fix your opener problems.
Up-down adjustment arrows utilize a yellow light and are found on LiftMaster commercial jackshaft openers. Wall-mounted residential openers with Wi-Fi connectivity also use these diagnostic codes.
Here is a rundown of the codes and their meanings. The section also recommends a solution for each problem associated with the various diagnostic codes.
UP Arrow Flashes once, Down Arrow Flashes once
This happens when the safety sensors are installed but not connected or not installed altogether. The code will also flash if the safety sensor wires are broken.
When any of these happens, the garage door will not close.
What to do
Inspect the sensor cables for breakage or disconnected parts. Install the sensors or connect them if they are not.
UP Arrow Flashes once, Down Arrow Flashes twice
Your opener will send this code if the safety reversing wires have a short or are reversed. This will prevent the door from closing.
How to fix it
The cables and their respective terminals on the motor unit are color-coded. Check to see if any colors don’t match, and ensure the right cable is connected to the appropriate terminal to fix the problem.
The UP Arrow Flashes once, Down Arrow Flashes three times
This code indicates that the door control wires have a short or the door control is malfunctioning. A faulty door control will not operate the garage door. The same applies to shorted door control wires.
What to do
Inspect the door control cables at their respective staple points to ensure each wire is in the corresponding terminal.
If the cables are in their correct connection points, test the door control for a malfunction and replace it if the test is positive.
The UP Arrow Flashes once, Down Arrow Flashes four times
This error code appears when your garage door opener has misaligned safety reversing sensors. The arrow buttons will also blink this way if the sensors are momentarily obstructed.
What to do
Realign any misaligned sensors or remove the obstruction causing the error code. The sensors will be aligned when the sensor lights both shine a solid light.
The UP Arrow flashes once, Down Arrow flashes five times
This error code may indicate that your opener has a broken spring or some other obstruction, such as an engaged door lock.
What to do
Disengage the opener and operate the door manually to inspect the problem. If you have a broken spring, replacing it should fix the issue.
Alternatively, remove the lock or replace the opener’s logic board if both solutions don’t work.
UP Arrow flashes twice; Down Arrow flashes five times
This error code usually indicates a problem with the logic board on your opener. The garage door will not move or produce a sound when this problem occurs.
What to do
Replace the logic board to fix the problem.
UP Arrow flashes three times; Down Arrow flashes once
You can see this error code if the logic board malfunctions. The garage door will likely move slightly and then stop.
What to do
Try activating the garage door again. If the problem persists, install a new logic board.
UP Arrow flashes four times; Down Arrow flashes six times
This happens when something blocks the safety reversing sensors momentarily or if they are misaligned.
What to do
Realign the safety sensors on your unit to correct the problem. For a temporary obstruction, remove any object in the garage doorway that may be blocking the sensor eyes.
The below video shows how to fix error codes in a Liftmaster 8500w
Conclusion on Liftmaster Flashing Light Codes
Do not rush to call a technician the next time your Liftmaster garage door opener malfunctions. Instead, count the number of times the light flashes and use this guide to identify the source of the problem.
Once you have located the issue, decide whether it is something you can fix on your own or one that requires a technician.
With this guide, you should be able to fix the majority of the problems with your Liftmaster garage door opener by following the recommended instructions.
We hope this guide helps you save money on your next fixes. Please share your experience in the comments.