Openers · Lisgar
Photo-Eye Sensor Alignment or Replacement in Lisgar
There are no sensors at the floor at all, or a previous owner has wired the pair together up beside the motor so the beam never crosses the doorway.
In plain words
By the end of the visit you have a door that closes from every control and reverses the instant the beam is broken, a sensor pair mounted level at the right height with steady indicator lights, wiring that is secured and out of harm's way, and a written note of what was found and what was changed. The technician walks you through the two tests you can repeat monthly, points out which light is which, and leaves the opener's diagnostic chart where you can find it. It is a small job that puts a large piece of your door's protection back in service.
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
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.
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.
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
Track-mount sensor brackets
Insulated wire staples
Multimeter
Concrete anchors
Protective wire channel
Photo-Eye Sensor Alignment or Replacement
What affects the quote
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.
Force and travel adjustment alongside
If the reversing turns out to involve a travel limit set long or a force setting made in summer, adjusting and re-testing those settings is included as a small extra step.
Length and route of the wire run
A damaged section near a sensor is a short repair. A fresh run from the motor to both sides of the doorway takes longer, more so where the wire is buried in a finished ceiling.
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?
- What do the two small sensor lights show: both steady, one dark or flickering, or both dark?
Photo-Eye Sensor Alignment or Replacement: questions
QuestionsDo sensors wear out with age?
They do, slowly. The infrared emitter and the receiver dim over many years, lenses craze or cloud from sun and salt, housings crack, and water finds its way in at floor level. A pair that needs re-aligning more and more often, or whose light drifts between steady and flickering with nothing touched, is usually ageing. Because pairs are matched to the opener, an older opener is worth identifying early so the right replacement is on hand.
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.
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 RepairThe door closes, touches the floor, then climbs straight back up as if it hit something.
- Belt-Drive Opener RepairAfter the power came back you pulled the red cord to get the car out.
- 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.