Garage Door Opener Safety Sensors - Rail Parts, Other

Replacement garage door sensors (safety reversing sensors, also called photo eyes) for LiftMaster, Chamberlain, Craftsman, Genie, Linear, Sommer, Marantec, Hormann, Allstar and Wayne Dalton openers, plus commercial photo eyes. The two sensors sit about 6 inches above the floor on each side of the door. One sends an invisible beam to the other, and if anything breaks the beam while the door is closing, the opener stops and reverses.
Door won’t close or the opener lights blink? Check the sensor lights first. Usually the sensors are just misaligned, dirty or have a loose wire, and nothing needs replacing. The guide below the products shows what each light colour means and how to align them. If a sensor is cracked or stays dark with good wiring, replace it with the sensor kit made for your opener brand: for example the LiftMaster 041-0136 fits LiftMaster, Chamberlain and Craftsman openers made since 1997.
Step by step for every brand: how to fix garage door sensors (light colors, alignment, wiring test). Opener won't run at all? Garage door won't open.
Also here: sensor brackets and sensor guards that protect the eyes from cars, bikes and brooms.
What the sensor lights mean
| Sensor lights | What it means |
|---|---|
| LiftMaster / Chamberlain / Craftsman: amber and green both steady | Normal. Amber = sending sensor, green = receiving sensor. |
| Green LED blinking | Misaligned or something is blocking the beam. |
| Amber on, green off | Wiring problem at the receiving sensor. |
| Both off | Wiring problem at the sending sensor, or no power to the opener. |
| Genie Safe-T-Beam: red and green both steady | Normal. Red = sending, green = receiving. |
| Red blinks 2 times | Misaligned or blocked. |
| Red blinks 3 times | Interference, often direct sunlight. |
LiftMaster openers also flash a code: the LEARN button flashes 4 times every 10 seconds, or the up arrow flashes 4 times and the down arrow 6 times, when the sensors are blocked or misaligned.
How to align garage door sensors
- Clear anything in the beam and wipe both lenses.
- Loosen the wing nut on the receiving sensor (green LED).
- Point the two lenses straight at each other until the green LED glows steady, then tighten the wing nut.
- Test: close the door with a 2x4 laid flat in the doorway. The door must reverse when it touches it.
Mount the beam no higher than 6 inches above the floor. If sunlight hits the receiving sensor, swap the two sensors to opposite sides of the door or add a sun shield.
Replacement sensors by brand
| Opener brand | Sensors and parts |
|---|---|
| LiftMaster / Chamberlain / Craftsman | 041-0136 sensor kit, brackets, extension brackets, sun shield |
| Genie | GSTB-BX Safe-T-Beam kit, Series II extension kit |
| Linear / Sommer / Marantec | HAE00087, Sommer 7012V001, Marantec 97246 |
| Hormann / Allstar / Wayne Dalton | EL201, Allstar 108994, 252118 |
| Commercial operators | LiftMaster CPS-U and more monitored photo eyes |
Protect sensors from bikes and bins with Sensor Guards. Need new wire? See opener wire. Questions? Call 877-379-4947.
More help: full garage door sensor guide · door won't open · reset the opener.




