Count the number of times the operator light blinks after a failed operation. The flash pattern indicates the error. Select your operator brand below.
LiftMaster / Chamberlain — Error Codes
Safety sensors (photo eyes) open or disconnected
Check photo eye alignment and wiring. Both LEDs should be solid.
Safety sensors shorted or wiring fault
Inspect wiring between operator and photo eyes. Look for pinched, cut, or shorted wires.
Door control wired to wrong terminal
Verify the wall button is connected to the correct terminals on the operator (not the safety sensor terminals).
Safety sensor eyes slightly misaligned
Photo eyes are communicating but marginal. Clean lenses and realign for solid LEDs.
Motor thermal overload or RPM sensor fault
Let the operator cool for 15 minutes. If it continues, check for mechanical resistance in the door.
Motor running too long / travel limit issue
Adjust travel limits. The operator may be running past its endpoints.
Operator needs reprogramming
Re-learn travel limits: hold the LEARN button, then program open/close limits per the manual.
MyQ / Wi-Fi communication error
Check Wi-Fi connection. Power cycle the operator and router.
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