Garage Door Opener Safety Sensors
If your door reverses, won't close, or the opener lights blink, the safety sensors (photo eyes) are the most common cause. These infrared eyes mount near the floor on each side of the door and stop it from closing on an obstruction. We stock OEM replacement safety sensors and photo-eye sets for LiftMaster, Chamberlain, Genie, Linear and more.
Blinking lights = sensor issue. Before replacing, check that the two sensors face each other, are wired correctly, and have clean lenses — a steady indicator light on both means they are aligned. Persistent blinking after cleaning and alignment usually means a sensor or wire has failed.
Wiring or board trouble instead? See opener circuit boards, or browse all garage door opener parts.
MMTC RAY-RT - Monitored Reflective Photocell UL325/2010SKU: RAY-RT$215.07 As low as $193.56Drop ShipWhat does this mean?MMTC RAY-RT monitored reflective photocell for gate and…
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MMTC FOS-1 - Optoeye Thru-Beam Photocell UL325/2010SKU: FOS-1$117.57 As low as $105.81Drop ShipWhat does this mean?MMTC FOS-1 Optoeye monitored thru-beam photocell for…
Diagnosing Photo-Eye Problems
Garage door safety sensors are required by law on every residential opener made since 1993. When they fail or misalign, the opener refuses to close the door (so it can't crush anything) and signals the fault by blinking its lights or beeping. Most issues are alignment or dirt, but sensors do wear out.
- Both LEDs solid: sensors are aligned and working.
- One LED off or flickering: realign the brackets until both lights are steady.
- Still blinking after alignment: clean the lenses, check for cut/pinched wires, then replace the sensor set.
- Sun glare in the lens can cause false trips — shade or reposition the affected eye.
Replace sensors as a matched pair (sending + receiving eye) and match them to your opener brand — LiftMaster/Chamberlain and Genie systems use different sensors and are not interchangeable.
Need help diagnosing? Call 877-379-4947 with your opener model and the blink pattern.
