Nothing is more frustrating than pressing your garage door remote only to have the door refuse to close. In many cases, the culprit is a faulty or misaligned safety sensor. If your garage door sensor is not working, the opener may prevent the door from closing or cause it to reverse before reaching the ground.
The good news is that many sensor problems can be identified and resolved without replacing the entire garage door system. This guide explains the most common causes, simple troubleshooting steps, and when it’s time to call a professional.
What Do Garage Door Safety Sensors Do?
Modern automatic garage doors are fitted with two safety sensors positioned near the bottom of each door track.
One sensor sends an invisible infrared beam while the other receives it. If anything interrupts that beam—such as a child, pet, vehicle or other object—the garage door automatically stops or reverses to prevent injury or damage.
This important safety feature is standard on modern garage door systems. When a garage door sensor is not working, the opener assumes the doorway is obstructed and prevents the door from closing.
Common Signs Your Garage Door Sensor Is Not Working
Your safety sensors may be faulty if you notice any of the following:
- The garage door won’t close using the remote or wall button.
- The door begins to close before reversing.
- The opener lights flash repeatedly.
- One or both sensor indicator lights are blinking or turned off.
- The garage door only closes when you hold the wall control button.
If you’re experiencing one or more of these issues, the safety sensors should be checked before assuming the opener itself is faulty.
1. Clean Dirty Sensor Lenses
The most common cause of sensor failure is surprisingly simple—dirty lenses.
Because the sensors sit close to the floor, they regularly collect dust, cobwebs, leaves and grime that can interrupt the infrared beam.
What to do
- Gently clean both sensor lenses using a soft, dry cloth.
- Remove any cobwebs or debris around the sensors.
- Check that no tools, boxes or stored items are blocking the beam.
Many homeowners discover their garage door sensor is not working simply because the lenses needed cleaning.
2. Check the Sensor Alignment
The two sensors must face each other perfectly for the infrared beam to connect.
Even a small bump from a bicycle, rubbish bin or lawn equipment can knock a sensor out of alignment.
How to check
- Look at the indicator lights on both sensors.
- Most systems display a solid amber light on the sending sensor and a solid green light on the receiving sensor.
- If either light is flashing or off, the sensors are likely misaligned.
- Carefully loosen the mounting bracket, adjust the sensor until both lights remain solid, then tighten it securely.
Minor alignment issues are one of the most common reasons a garage door refuses to close.
3. Inspect the Wiring
If cleaning and alignment don’t solve the problem, inspect the sensor wiring.
Over time, cables can become loose, damaged or disconnected through normal wear and tear.
Look for
- Frayed or damaged wires.
- Loose wire connections at the sensors.
- Loose terminals at the garage door opener.
- Rodent or accidental damage to cables.
If damaged wiring is found, it’s safest to have it repaired by a qualified garage door technician.
4. Check for Moisture or Water Damage
Garages are often exposed to moisture from rain, condensation and humidity.
Water entering the sensors or wiring can interfere with their operation.
What to do
- Look for signs of moisture around the sensors.
- Dry the sensors thoroughly.
- Check nearby wiring for corrosion.
- Improve drainage if water regularly enters the garage.
If water has damaged the internal electronics, replacing the sensors may be the most practical solution.
5. Consider Sunlight Interference
Many homeowners are surprised to learn that direct sunlight can affect garage door safety sensors.
Strong afternoon sunlight shining directly into the receiving sensor may overpower the infrared beam and prevent the door from closing.
Possible solutions
- Observe whether the problem only occurs during certain times of the day.
- Install a small sensor shield.
- Slightly reposition the sensors to reduce direct sun exposure.
If your garage door sensor is not working only during bright sunny conditions, sunlight interference could be the cause.
6. Replace Worn or Faulty Sensors
Like any electronic component, garage door safety sensors eventually wear out.
If you’ve completed all the troubleshooting steps and the problem continues, replacement may be necessary.
Common signs include:
- Constantly flashing indicator lights.
- Intermittent operation.
- Visible cracks or physical damage.
- Corrosion or weather-related deterioration.
- Sensors more than several years old that repeatedly fail.
Replacing faulty sensors is usually a straightforward repair that restores reliable and safe operation.
When Should You Call a Professional?
While many sensor issues are simple to fix, some problems require professional diagnosis.
Consider contacting a garage door specialist if:
- The door still won’t close after completing the basic checks.
- Wiring appears damaged or disconnected.
- The garage door behaves unpredictably.
- The opener makes unusual noises.
- The door drops suddenly or reverses unexpectedly.
- You need replacement sensors or electrical repairs.
A qualified technician can accurately diagnose the problem, carry out repairs safely and inspect the rest of the garage door system for potential issues.
Prevent Future Sensor Problems
Routine maintenance can help reduce unexpected breakdowns and extend the life of your garage door system.
We recommend:
- Cleaning the sensor lenses every month.
- Keeping the area around the sensors free of clutter.
- Inspecting cables for signs of wear.
- Testing the safety reverse function regularly by placing an object in the sensor beam.
- Scheduling professional servicing to ensure the entire garage door system operates safely.
These simple maintenance steps can help prevent future sensor problems and improve the reliability of your garage door.
Final Thoughts
A garage door sensor not working is one of the most common garage door issues, but it’s also one of the easiest to diagnose.
In many cases, cleaning the lenses, realigning the sensors or removing an obstruction is all that’s required to restore normal operation.
Because safety sensors protect your family, pets and property, it’s important not to ignore ongoing issues. If basic troubleshooting doesn’t solve the problem, having your garage door professionally inspected is the safest option.
About OzStrong Garage Doors
At OzStrong Garage Doors, we supply, install, service and repair automatic garage doors throughout Sydney, Penrith, Campbelltown and Windsor.
Our experienced team works with roller doors, sectional doors, panel lift doors, tilt doors, garage door openers, remotes, safety sensors and complete garage door upgrades.
If your garage door sensor is not working, your garage door won’t close properly or the system is behaving unpredictably, we can quickly diagnose the fault, repair or replace damaged components, and restore the safe, reliable operation of your garage door.
