Openers · Peterborough
Photo-Eye Sensor Alignment or Replacement
After a cold night the door stays open until the garage warms up. There is frost on the sensor lenses and a ridge of salty slush piled against the brackets where the snow blower was parked.
Photo-Eye Sensor Alignment or Replacement
In plain words
Photo-eye sensor service brings back the invisible beam that runs across the bottom of your doorway and lets the opener close with confidence. A technician clears the path, checks each sensor's indicator, tests the low-voltage wiring back to the head unit, and reads the opener's own diagnostic lights to tell an obstruction from a wiring fault. Brackets are straightened and refastened, lenses cleaned, and the pair aimed at each other at the same height no higher than 15 cm off the floor. If a sensor has failed, a matched pair for that opener family goes in. The visit ends with a beam test and a contact reversal test.
How the visit goesSince shelving went up along the garage wall, the door will not close and both sensor lights are dead. A screw or staple may have gone through the thin wire that runs from the opener to the sensors.
Peterborough
How the visit goes
Reading the two small lights
Most sensor pairs carry an indicator on each side, though some older models light only the receiver, so the technician checks that model's own chart first. On most openers the sending eye shows one colour and the receiving eye another, and both should glow without a flicker. If the sending light is steady and the receiving light is dark or blinking, the beam is not landing where it should: misalignment, an obstruction or a dirty lens. If both are dark, the pair has no power, pointing up the wire to a cut, a loose terminal or reversed connections. The technician also nudges each bracket gently while watching the light; a flicker on touch means a loose mount.
Proving it with the two tests
No sensor job is finished on a steady light alone. The door is closed from the wall control and from a remote, and while it is on its way down an object is passed through the beam; the door must stop and return to fully open. Then a 2x4 is laid flat on the floor under the centre of the door and the door is closed onto it; it must reverse on contact. Both are repeated, the opener's diagnostic light is confirmed clear, and any app or hub reporting a sensor code is refreshed. The customer watches the tests so the normal behaviour is seen, not described.
Wiring that stays put
The wire between the head unit and the sensors has been secured along the ceiling and walls, clipped clear of the track and, where it was exposed, run inside a protective channel. Two things keep it that way. First, when anything is fastened to those walls or that ceiling, from shelving to a bike hook to drywall, look for the thin wire before driving a screw or a staple. Second, if mice have been in the garage, a chewed wire is a common sign, so a dark sensor light after a sighting is worth a look at the run. Either way, the sensor lights will tell you the moment the circuit is open.
Photo-Eye Sensor Alignment or Replacement
In the van
- Concrete anchors
- Receiving-eye sun shade
- Wire connectors
- Multimeter
- Matched photo-eye sensor pair
What affects the quote
Same fees day, night or weekend
1Door-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.
2Sun and reflection remedies
Swapping the sensors side to side is a small addition when the wiring reaches. Fitting a shade, or extending the wire so the receiver can move, is a little more and is listed on its own.
3Opener make and generation
Sensor pairs are matched to the opener family, and some models take a kit with brackets and wire while others take sensors alone. The head unit label sets which pair is needed and how it is priced.
Photo-Eye Sensor Alignment or Replacement: questions
Could the wiring be the problem rather than the sensors?
Frequently. The sensors are fed by a thin two-conductor wire from the head unit that crosses the ceiling and drops down both sides of the door, and it is pierced by staples, cut by shelving screws, chewed by mice or pulled from its terminals more often than a sensor fails. Both sensor lights dark, or an opener code for an open or reversed circuit, points to the wire. The technician tests the run with a meter and repairs or replaces the damaged section.
What tests are done before the technician leaves?
Two, and you are invited to watch. With the door closing, an object is passed through the beam and the door has to halt and climb back to the top. A 2x4 laid flat beneath the door's centre comes next; closing onto it must make the door back off on contact. The door is also run from the wall control and a remote, the opener's warning flashes are confirmed gone, and both sensor lights are shown steady.
What can I check myself before calling?
Three things, all safe. Look along the floor between the sensors for anything in the path, including snow, leaves or a cobweb across a lens. Look at the two sensor lights and note whether one is dark or flickering, or both are dark. Press close and count the flashes of the opener light. If moving an object or wiping a lens brings the receiving light back on steadily, the door may close normally again; if not, those observations make the visit shorter.
Openers & Access
Photo-Eye Sensor Alignment or Replacement near you
Shops, warehouses and service bays in Peterborough have their own list: rolling steel doors, heavy sectional doors, industrial operators, safety edges and high-cycle springs. Alongside our residential work, we service and replace all of these and can set up a maintenance schedule that fits your operating hours.