

Openers · Mount Hope
Photo-Eye Sensor Alignment or Replacement in Mount Hope
The door will only go down while a finger stays on the wall button; let go and it stops or reverses.
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 goesThe small light on one of the sensors near the floor has gone dark, or it flickers when someone walks past the track. The other one glows steadily. The door refuses to close from the car.
Photo-Eye Sensor Alignment or Replacement
How the visit goes


Following the wire home
When the lights or the code point to the circuit, the low-voltage wire is followed from each sensor to the head unit. The technician looks for staples driven through the insulation, wire pinched behind a track bracket, sections chewed by mice, cuts where shelving or drywall screws went in, splices that have corroded, and terminals at the head unit that are loose or connected the wrong way round. A meter confirms continuity and polarity rather than guessing. Where the wire disappears into a finished ceiling, the readings at each end tell whether the hidden section is sound or whether a fresh run is the tidier answer.
Bringing the pair back to the doorway
Sometimes the sensors exist but have been defeated: taped face to face next to the head unit so the circuit is always satisfied and the door closes on anything. The technician separates the pair, checks that both still work, and mounts them where they belong on each side of the opening, low to the floor and facing each other. New wire is run down each side, brackets are fitted, and the alignment is set. The opener is then made to prove itself with the beam test, and the household is shown why the pair matters and how to keep it working, so the shortcut is never tempting again.
If it ever reverses again
Should the door start bouncing back up in the future, you know the order to check. Look along the floor for anything in the beam. Look at the two sensor lights for a dark or flickering one. Look at whether the door backs up as soon as it starts or only after touching something, since the second points to the door's settings rather than the beam. Note whether the opener light is flashing and how many times. With those four facts the cause is usually obvious, and if a visit is needed, the technician arrives already knowing where to begin.
Photo-Eye Sensor Alignment or Replacement
In the van
Wall or floor angle brackets
Two-conductor low-voltage wire
Concrete anchors
Multimeter
Wing nuts and carriage bolts

Photo-Eye Sensor Alignment or Replacement
What affects the quote
Opener 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.
Bracket condition
A bracket that can be straightened costs little time. One that is cracked, rusted through or missing is replaced, and a change from track clips to wall or floor brackets adds anchors and mounting work.
Winter conditions on the day
Snow and ice packed against the brackets, a frozen bottom seal or a frozen floor where anchors must go all add a little clearing and care before the sensor work itself can start.
What to have ready
- Does it happen at all hours, or mainly on bright mornings or late afternoons?
- Which direction does the garage door face?
- Is there frost, snow, slush or salt around the sensors in winter?
Photo-Eye Sensor Alignment or Replacement: questions
QuestionsDo 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 should I clean the lenses?
Gently, with a soft dry or lightly damp cloth, the way you would clean eyeglasses. Never scrape a lens or use a solvent, since a scratched or clouded lens scatters the beam. Wipe both sensors, then check that the receiving light comes on steadily. If a lens frosts on cold mornings, give it a few minutes to clear or dry it with a cloth. A quarterly wipe keeps dust, cobwebs and salt film from building up.
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 rail shakes when the door runs.
- 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 ReplacementPress the button and the motor hums, but the door stays exactly where it is.