Liftmaster Garage Door Opener Error Codes

Check out this list of error codes and find out what’s wrong with your Liftmaster garage door opener. To begin with, count the number of flashes (separately up and down). Now, you can refer to the table below and learn how to troubleshoot the device depending on the symptom.

Liftmaster 8550 Garage Door Opener Error Codes

UP DOWNSYMPTOMCAUSERESOLUTION
1 flash1 flashThe garage door opener will not close and the light(s) will flashSafety sensors are not installed, connected, or wires may be cutInspect sensor wires for a disconnected or cut wire(s). If the sending sensor with the amber LED is NOT lit, check the wire and connections for that sensor. If sending sensor LED is lit, check the wire connections leading to the receiving sensor (green LED). Reattach wire or replace wire (22 gauge wire) as needed. If pre-wired home, check the splices. Close the garage door using the remote control or the door control.
1 flash2 flashThe garage door opener will not close and the light(s) will flashSafety sensor wire shorted or reversedInspect sensor wire for incorrect wiring or a pinched wire. If the sending sensor (amber LED) is not lit, check the wire leading to and from that sensor. Check staple points. If sending sensor LED is lit, check the wire leading to the receiving sensor (green LED). Reattach wire or replace wire (22 gauge wire) as needed. If pre-wired home, check the splices. Close the garage door using the remote control or the door control.
1 flash3 flashWall-mounted door control will not functionThe wires for the door control are shorted or the door control is faultyInspect door control wires for a short (staple in wire), replace wire (22 gauge wire) as needed. After installing new door control wires, if door control still does not operate garage door opener, replace the door control.
1 flash4 flashThe garage door opener will not close the door and the light(s) flashMisaligned or obstructed safety sensorsRealign the receiving sensor (green LED) by ensuring the LED is steady and not flickering. A flicker of the safety sensor LED indicates a misalignment. Make sure nothing is hanging or mounted on the door interrupting the sensor’s path while closing. Close the garage door using the remote control or the door control.
1 flash5 flashThe garage door opener clicks but no movementBad logic boardReplace the logic board.
The opener runs approximately 6-8” and stops and/or reversesCommunication error to travel moduleDisconnect all power, remove cover, and locate the travel module. Ensure the wires for travel module are connected, if wires are connected, then replace the travel module.