Garage Door Opener Blink Code Decoder

The LiftMaster/Chamberlain entries come from the Chamberlain Group support knowledge base: on most units made since the mid-2010s, the up and down arrow buttons on the motor head double as diagnostic LEDs, flashing a two-number code (up-arrow count, then down-arrow count) that maps to a specific fault — 1-1 sensors not connected, 1-2 sensor wire shorted or reversed, 1-4 sensors misaligned, 4-6 travel not programmed, and so on. The 10-flash main-light signal is the older, better-known cousin: 10 flashes of the opener's light bulb when the door refuses to close means a safety-sensor obstruction or misalignment. Some post-2022 boards dropped that feature, which is why the arrow codes are the more reliable place to look. Genie entries follow Genie's support documentation for red-LED blink counts on the motor head (3 = limit switch, 4 = Safe-T-Beam) plus the LED language on the Safe-T-Beam eyes themselves.

The DIY-or-pro verdict on each code is a safety and economics call, in that order. Sensor alignment, lens cleaning, wall-button swaps, and limit reprogramming are genuinely safe fixes — low-voltage wiring, no stored tension — and most of these codes clear for free. The pro codes are the ones pointing inside the motor head (RPM sensor, motor circuit, a board that won't hold its travel), where the honest question is repair versus a new opener installed at $250–$550, especially past the 10–15-year mark. One caution that applies across brands: if a force or travel code coincides with a door that's heavy on the manual lift test, the opener is the messenger, not the problem — that's a spring issue, and springs are under tension a homeowner should never touch.

This decoder covers the common, well-documented codes, not every variant of every model year — always cross-check your model's manual, and treat any code we don't list as a tech question. Garage Door Repair Network is a referral service: we route requests to independent local opener techs, and the lead form under each result carries your exact code so the tech shows up knowing what to bring. Code tables are re-checked annually against Chamberlain Group and Genie support documentation.

Estimates only — independent local providers quote their own pricing. Data last reviewed 2026-07.