Quantztown Garage Door ServicesService bulletin 3 of 3
Photo-Eye Sensor Alignment or Replacement: how the work is done
Photo-eye sensor service brings back the invisible beam that runs across the bottom of your doorway and lets the opener close with confidence.
Markham, Ontario · Garage Doors · open 24/7

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.
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.
Two lights to glance at
You leave knowing what normal looks like at the floor. Most sensor pairs carry a small indicator on each side, often in different colours for sender and receiver, though some older pairs light only the receiver; the model's own chart tells you what steady and flickering mean. A dark or flickering light on the receiving side means the beam has been lost, usually because a bracket was bumped or something is in the path, and two dark lights mean the pair has lost power along the wire. A glance at those lights before calling anyone tells you most of what the technician would look at first, and often the fix is moving whatever is leaning on the bracket.