Limit switch fault

A Genie opener blinking its red LED three times on the motor head is reporting a limit-switch fault: the opener can't confirm the door's open and closed positions, so it stops mid-travel or refuses to run. Genie's travel-limit system tracks where the door should stop, and when that system faults the opener plays it safe by halting.

The DIY step is re-programming the open and close limits per your model's manual, and while you're at it, check that the carriage and the limit components on the rail move freely rather than binding. If the limits set and hold, you're done. If they won't set, or the three-blink fault keeps coming back after reprogramming, the switch assembly or the board is failing — recurring limit faults are a hardware problem and the point to bring in a Genie tech.