

Openers · Adelaide-Metcalfe
Photo-Eye Sensor Alignment or Replacement in Adelaide-Metcalfe
After a cold night the door stays open until the garage warms up.
In plain words
Some sensor problems keep a schedule. A receiving eye that faces the low sun on winter mornings is flooded with light and loses the beam until the sun moves on, and a lens that frosts overnight in an unheated garage clears itself by noon. The service sorts these out for good: the sensors are swapped side to side so the receiver faces away from the light, or a small shade is fitted, and lenses and brackets are cleaned and reset above the line where slush collects. The door then closes at any hour of the day and in any month.
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


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.
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.
A record of the work
You have a short written note of what was done: the opener make and model, what the diagnostic code and the sensor lights showed on arrival, whether the fault was alignment, wiring, sun or a worn sensor, what was replaced and where the new parts sit. It records the height the sensors were set at and that both tests were passed with you watching. That note is useful for a home inspection, for the next technician, and for you, because it shows what normal looks like on this door so a future change is easy to describe over the phone.
Photo-Eye Sensor Alignment or Replacement
In the van
Matched photo-eye sensor pair
Wing nuts and carriage bolts
Receiving-eye sun shade
2x4 test block
Track-mount sensor brackets

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.
Corrosion reaching the head unit
Where salt and water have travelled up the wire to the terminals, or the sensor terminals on the board are damaged, the repair extends beyond the pair and that is set out separately.
Protecting exposed wire
On a wall where the wire runs in the open, a slim protective channel or a re-route higher along the wall keeps bins, bikes and mice away from it, and is quoted as its own line.
What to have ready
- Which direction does the garage door face?
- Is there frost, snow, slush or salt around the sensors in winter?
- Does it happen at all hours, or mainly on bright mornings or late afternoons?
Photo-Eye Sensor Alignment or Replacement: questions
QuestionsWhat 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.
Do I need to be home for the work?
It helps. The technician needs access to the garage and the head unit, and the visit ends with a demonstration of the sensor lights and the two tests so you know what normal looks like. If you cannot be there, an adult who can open the garage is enough, and the written note left afterwards records what was found and changed. Having the strip of floor beside the door clear before arrival saves time either way.
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.
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 remotes only work from the end of the driveway now, and one of them disappeared with a set of keys last month.