Operation and controls
What are garage door photocells?
Garage door photocells are paired infrared safety sensors, mounted roughly 150–200mm above floor level on each side of a UK power-operated door, that detect when something breaks the beam across the opening and stop the door closing. They are a required safety feature under BS EN 12453 and a common source of nuisance faults, with realignment typically costing £80–£180.
How they work
One unit transmits an infrared beam, the other receives it. As long as the receiver detects an unbroken beam, the operator is free to close the door. If the beam is interrupted — by a person, pet, car bumper or a stray object — the operator stops the closing movement immediately and typically reverses the door back open.
Common photocell faults
Dust, cobwebs or a build-up of dirt on either lens can weaken or block the beam even with nothing actually in the way. Knocks from a car, bike or garden equipment can also nudge a unit out of alignment so the beam no longer lines up between transmitter and receiver. Both cause the same symptom — the door refusing to close, or reversing before it gets there.
Questions people ask
- Are photocells a legal requirement on UK garage doors?
- Photocells, or an equivalent safety measure, are required as part of the safety-in-use provisions of BS EN 12453 for power-operated doors. A door installed without any obstruction-detection system would not meet the standard.
- Can I clean photocells myself?
- Yes — wiping both lenses with a soft, dry cloth is a routine user-level task and does not involve the electrics or any safety-critical adjustment. If cleaning does not resolve the fault, alignment or wiring issues are best left to an engineer.
- Do all UK garage door types have photocells?
- Photocells are standard on power-operated roller, sectional and up-and-over doors. Manual doors, having no motor to sense resistance, do not use photocells since there is no automated closing movement to protect against.
UK standards and regulations referenced
- BS EN 12453:2017+A1:2021
- BS EN 12445
Related
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