Openers · Toronto
Photo-Eye Sensor Alignment or Replacement
You press the remote, the door drops a few centimetres, then climbs straight back to the top while the opener light blinks.
In plain words
Two small sensors face each other across the doorway: one sends an infrared beam, the other receives it. While the beam lands on the receiver, the opener will close the door; the moment anything interrupts it, the door stops and returns to open. Every sensor call comes down to why the receiver has lost the beam: an object, a bent bracket, a dirty or frosted lens, sun in the receiving eye, a broken wire or a tired sensor. The technician works through those in order, fixes the one that applies, and shows you the steady indicator lights that mean the pair is talking again.
How the visit goesOn bright mornings the door will not close, then by lunchtime it behaves itself. The garage faces the low sun, and the light reaches straight across the floor to one of the little black sensors.
Photo-Eye Sensor Alignment or Replacement
How the visit goes
Ruling out sun, frost and reflections
A sensor that misbehaves on a timetable is usually being blinded rather than broken. The technician notes which way the door faces, where the low sun reaches the floor in the morning and late afternoon, and whether a receiving lens looks into that light or into a reflection off a parked car, a white wall or fresh snow. Lenses are checked for frost, condensation and a film of salt, common in an unheated garage. A hand cupped over the receiving eye while the light is watched is a simple test: if the indicator settles when the eye is shaded, the fix is a side swap or a small hood rather than new parts.
Cleaning and protecting the lenses
Lenses are wiped with a soft cloth and a mild cleaner, never scraped, and the housings are checked for cracks that let in water. Sensors that have been sitting in the strip where slush and salt collect are raised within the permitted height range and their brackets sealed. On a wall where the wire runs exposed, a slim protective channel keeps it clear of bins and bikes. Where mice have been at the wire, the new run is routed higher along the wall and dropped straight down to each sensor. These small measures are what keep a repair from repeating the following winter.
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
Insulated wire staples
Track-mount sensor brackets
2x4 test block
Wing nuts and carriage bolts
Two-conductor low-voltage wire
Photo-Eye Sensor Alignment or Replacement
What affects the quote
Undoing an earlier shortcut
Sensors taped together beside the motor, mismatched pairs from different generations or a bypassed circuit are put right first, which means new wire down each side and fresh brackets at the doorway.
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.
Door-side findings
A balance problem, a stiff roller or a bottom seal that needs replacing sometimes shows up during testing. Those belong to their own service and are noted and quoted separately rather than hidden in the sensor work.
What to have ready
- What do the two small sensor lights show: both steady, one dark or flickering, or both dark?
- Is there frost, snow, slush or salt around the sensors in winter?
- Does the opener light flash when you press close, and how many times?
Photo-Eye Sensor Alignment or Replacement: questions
QuestionsMy opener has no sensors at all. Can they be added?
If the opener predates the entrapment-protection standard, which operators have had to meet since the mid-1990s, its board has no sensor circuit and a pair cannot simply be wired in. The positive news is that a modern operator brings the whole package: matched sensors, force reversal and a monitored circuit. The technician confirms the model first, because some units do have the terminals and simply had their sensors removed.
How high off the floor should the sensors sit?
Low. The industry checklist expects the beam no more than roughly 15 cm (6 in) up from the floor, so that a small child, a pet or a bicycle wheel breaks it. Both sensors are set at the same measured height and level with each other, since a difference of a couple of centimetres is enough to lose the beam. Within that rule the technician can raise them a little to keep them out of the strip where slush collects.
Why does my door start to close and then go straight back up?
Often the opener believes something is in the doorway, which happens when the receiving sensor stops seeing the beam, whether from an object in the path, a bracket knocked out of line, a dirty or frosted lens, sun in the receiving eye, or a damaged wire. Binding, a force setting or the door arm can cause the same symptom, so the sensor lights and the opener's flashing pattern are read first, and the technician fixes the cause they point to rather than guessing.
Related services
- Chain-Drive Opener RepairPress the button and the opener hums for a second, then quits.
- Belt-Drive Opener RepairPress the remote and the motor runs its full cycle, lights on, the usual whir, but the door does not move a centimetre.
- Garage Door Opener ReplacementThe remotes only work from the end of the driveway now, and one of them disappeared with a set of keys last month.