How to Align Garage Door Sensors

Tools You’ll Need

• Step ladder
• Soft cloth or microfiber towel
• Phillips and flathead screwdrivers
• Carpenter’s level (optional)
• Replacement sensor mounting brackets (if damaged)

Step-by-Step: How to Align Garage Door Sensors

1. Power Down the Opener Unplug your garage door opener or switch off the circuit breaker to prevent accidental activation.
2. Clear the Sensor Lenses
   • Wipe each sensor lens with a clean, dry cloth.
   • Remove any spider webs, dirt, or obstacles that could block the infrared beam.
3. Check LED Indicators
   • Re-power the opener.
   • Observe each sensor’s LED: one side (usually the “sending” eye) should glow solid; the other (“receiving” eye) should glow solid when properly aligned.
4. Loosen Mounting Brackets
   • Use a screwdriver to slightly loosen the screws on each sensor bracket—just enough so you can pivot them by hand.
5. Align Horizontally
   • Adjust sensors so their lenses point directly at each other.
   • Use a level across the two sensor faces to ensure they’re at the exact same height.
6. Fine-Tune Vertically
   • Pivot each sensor up or down in small increments until both LEDs turn solid green (or amber, depending on your model).
7. Tighten Hardware
   • Once LEDs indicate a “good” beam, carefully tighten the bracket screws—avoid jostling the sensor.
   • Recheck LEDs to confirm they remain solid after tightening.
8. Test the Door
   • Press “Close” on the wall-mounted button or remote.
   • Watch the door’s operation: it should close fully without reversing.

Troubleshooting LiftMaster Error Code 4-6

• Code Meaning: Error 4-6 on LiftMaster openers signals “Safety Sensors Misaligned.”
• Quick Fix: Follow the alignment steps above.
• Persistent Issues:
  • Inspect wiring for frays or loose connections at the sensor terminals.
  • Ensure sensors are mounted no more than 6 inches above the floor and within 3–5 feet of the door track.
  • Replace sensors if LED never solidifies after alignment attempts.

How to Fix Garage Door Sensors: Beyond Alignment

• Wiring Repairs: If alignment fails, check for broken wires between the sensors and opener. Splice or replace damaged cables.
• Sensor Replacement: Modern sensors cost $50–$100 per pair. Replace both at once to ensure matched sensitivity.
• Bracket Upgrades: Swap out bent or rusted mounting brackets for sturdier, adjustable models that lock alignment in place.
• Professional Calibration: For custom installations or persistent faults, schedule a professional inspection to test voltage, resistance, and opener logic boards.

Preventative Maintenance Tips

• Monthly Checks: Wipe lenses and check LEDs each month to catch misalignment early.
• Seasonal Inspection: Cold weather can contract mounts; warm months may expand them—re-check twice yearly.
• Rodent Protection: Secure wiring in conduit to prevent chewed cables causing sensor failures.