Openers · Barrie
Photo-Eye Sensor Alignment or Replacement
Since shelving went up along the garage wall, the door will not close and both sensor lights are dead.
In plain words
The sensors are only as good as the thin two-conductor wire that links them to the opener. It runs from the low-voltage terminals on the head unit along the ceiling and down each wall to the floor, stapled as it goes, and it is easily pierced, cut during renovations, chewed, or pulled loose at the terminals. When both sensor lights are dark, or the opener's code says the circuit is open or reversed, the technician tests the run end to end, repairs the damaged section or replaces the whole run, checks polarity at the terminals, and clips the new wire clear of the track.
How the visit goesYou press the remote, the door drops a few centimetres, then climbs straight back to the top while the opener light blinks. Nothing is under the door. It has done this every evening this week.
Photo-Eye Sensor Alignment or Replacement
How the visit goes
Making sure it is the sensors and not the door
A door that reverses on the way down has two possible reasons, and only one of them lives at the floor. If the door touches something, including a bottom seal frozen to the slab, a travel limit set slightly long or a stiff door in cold weather, the force setting sends it back up. That looks like a sensor fault from the driveway but calls for a different fix. The technician checks whether the door reverses before it moves or after it meets resistance, watches the sensor lights during the cycle, and tries the door with the beam deliberately shaded. The answer decides whether the work stays with the sensors or moves to the settings.
Resetting the alignment
Alignment is done with the door open and the lights in view. The technician sets both sensors to the same measured height, loosens the wing nut on the receiving side, and turns the sensor a fraction at a time until its indicator changes from dark or flickering to steady. The nut is tightened while the light is watched, because a sensor can drift as the fastener bites, and the sending side is treated the same way. Brackets are checked for play and the wire is re-clipped so it cannot tug the sensor out of line. A steady light on both sides, held through a few door cycles, is the standard.
The monthly beam test
The habit worth keeping takes about a minute. Once a month, with the door open, press close on the wall control and, as it moves down, pass a broom handle through the beam near the floor. The door should stop and climb back to fully open. Then lay a 2x4 flat under the middle of the door and close onto it; the door should touch it and reverse. If either test fails, stop using the opener; close the door first if it is not already closed, then use the manual release, and get help moving it by hand if it feels heavy or will not hold. A door that passes both tests is doing its job.
Photo-Eye Sensor Alignment or Replacement
In the van
Receiving-eye sun shade
Concrete anchors
Wire connectors
Wing nuts and carriage bolts
2x4 test block
Photo-Eye Sensor Alignment or Replacement
What affects the quote
Wall or floor mounting with anchors
Mounting into concrete or masonry rather than onto the track means drilling, anchors and sealing against water, which takes more time than clipping to the rail.
Type of kit
Some replacement kits contain only the two sensors with connectors, while others include brackets and a full length of wire. The kit that suits the opener and the state of the existing hardware is what is quoted.
Access to the doorway and the head unit
A clear strip along the floor and a reachable head unit make for a direct job. Shelving, vehicles or stored goods that must be moved to reach the sensors, wire or terminals add time.
What to have ready
- Does the opener light flash when you press close, and how many times?
- When you press close, does the door bounce back, sit still, or go down only with the wall button held?
- Which direction does the garage door face?
Photo-Eye Sensor Alignment or Replacement: questions
QuestionsCan any sensor pair be used with my opener?
Not any, no. Sensors are matched to the opener's make and generation, and a board from one era may ignore sensors from another even when the wires fit. The technician reads the model from the head unit label and fits the pair listed for it. Some operators accept a documented universal pair, and those are used where the maker lists them as suitable; on a very old unit with no compatible pair, a modern operator is the way forward.
The opener light blinks when I press close. Is that the sensors?
Very often, yes. A blinking bulb after a close command is the opener reporting that its sensor circuit is unhappy, and the count of blinks is the message: one common family uses ten flashes for the sensors, while a short two-flash pattern usually means the wall control's lock button is on. Newer units add arrow codes that separate a blocked beam from a cut or reversed wire. Counting the flashes and telling the technician the make helps identify the cause before the visit.
Do both sensors get replaced together?
Yes. The sending and receiving sensors are made and sold as a matched pair for a given opener family, and the head unit expects both to be from the same generation. Fitting a pair also means both lenses, both indicators and both mounting points are fresh at the same time, so the alignment holds and the next check is simpler. A single sensor from an unrelated kit is where mystery faults come from.
Related services
- Chain-Drive Opener RepairThe door closes, touches the floor, then climbs straight back up as if it hit something.
- Belt-Drive Opener RepairHalfway up, every single time, the door hesitates and there is a ratcheting sound from the motor head, then it carries on.
- Garage Door Opener ReplacementThe opener in the ceiling is older than the car parked under it.