Why Garage Door Sensors Go Bad Over Time — and When to Replace Them

Your garage door sensors are small, but they play one of the biggest roles in keeping your home safe. These tiny devices prevent the door from closing on people, pets, or objects by using an invisible beam of light to detect anything in the door’s path. But like all parts of your garage system, sensors can wear out or fail over time, and when they do, your entire garage door can stop working properly.

At Sunline Garage Doors, we often get calls from homeowners thinking their opener or motor is broken — when in reality, it’s just a pair of worn-out sensors.

Let’s break down why this happens and how to tell if it’s time for a replacement.

How Garage Door Sensors Work

Garage door safety sensors (also known as photo eyes) are located near the bottom of your door tracks, about six inches off the ground.
They work in pairs:

• One emits an infrared beam

• The other receives it

When that beam is interrupted — by a person, pet, or object — the system tells your opener to stop or reverse, preventing injury or damage.

Why Sensors Go Bad Over Time

Even the best sensors aren’t built to last forever. Over the years, they can become misaligned, dirty, or completely fail due to:

• Dust and debris buildup blocking the beam

• Moisture damage or corrosion from rain or humidity

• Wiring wear and tear inside the garage

• Sunlight interference (especially in sunny places like houses facing west or east)

• Physical bumps from tools, bikes, or kids playing nearby

On average, garage door sensors last 5–10 years, depending on usage, climate, and maintenance.

Common Signs of Failing Sensors

If your garage door won’t close or acts up randomly, your sensors might be the culprit. Look for:

• Blinking or dim indicator lights on one or both sensors

• The door reverses immediately after touching the floor

• You have to hold the wall button to close the door

• The door won’t close at all, even though nothing is in the way

A quick cleaning or realignment sometimes fixes the issue — but if the sensors are cracked, water-damaged, or no longer responding, it’s time for a replacement.

The Importance of Replacing Bad Sensors

Faulty sensors don’t just cause inconvenience — they can also create safety risks. A door with bad sensors may fail to stop when something’s in the way or may refuse to close, leaving your garage unsecured.

Replacing them ensures:

• Proper safety compliance (required by law for all modern openers)

• Reliable operation of your opener system

• Peace of mind knowing your garage is safe for family and pets

Professional Sensor Inspection & Replacement

At Sunline Garage Doors, we don’t just swap out parts — we test, realign, and recalibrate your entire safety system.
Whether your sensors need a simple adjustment or a full replacement, we’ll ensure your garage door works safely and efficiently.

If your garage door blinks, reverses, or refuses to close, it’s best to schedule an inspection before the problem worsens.

Keep your garage door safe and reliable.
Contact Sunline Garage Doors today for sensor testing and replacement services in Orange County and surrounding areas.
We’re just a call away from restoring your peace of mind and your garage’s performance.