Blind, Blocked, or Broken — Usually in That Order
When an automatic door ignores the people walking up to it, everyone assumes the sensor has died. In our automatic door repair experience, actual sensor failure sits behind three more mundane causes: the sensor cannot see (dirty or covered lens), the sensor is looking the wrong way (knocked out of alignment), or something has changed in its view (new signage, a plant, a hanging decoration triggering or masking its zone).
That ordering is good news, because two of the three cost nothing to check.
The Owner’s Checklist
Clean the lens. Wipe the sensor window above the door with a dry cloth. Dust film, cobwebs, paint overspray and stickers all blind sensors gradually — the door “gets lazy” over weeks before failing outright.
Look for new obstructions. Anything recently hung near the door — banners, mobiles, promotional standees — can sit inside the detection zone and confuse it.
Check alignment. A sensor head visibly tilted, twisted or dangling has been knocked — cleaners’ brooms and delivery trolleys are the usual suspects. Do not bend it back by guesswork; the sweep angle needs setting properly.
Power-cycle. Switch the door off at its isolator, wait thirty seconds, switch on. This resets the controller and clears a share of electronic sulks.
One sensor or both?
Remember the door has two sensor systems — activation (opens the door) and safety (holds it open). A door that won’t open has an activation problem; a door that won’t close has a safety-beam problem. Naming which saves diagnostic time. Our guide on how door sensors work covers the split.
When It’s Past DIY
If the lens is clean, the view is clear and a power-cycle changes nothing, the fault has moved into wiring, the sensor unit or the controller — territory for a technician with test equipment (our guide on what to expect from an automatic door service visit shows how that diagnosis runs). Loose connections at the header, water ingress after roof leaks, and aged sensor units are the common findings, and each is a quick swap once identified.
Sensor work is bread-and-butter for our repair team: we carry compatible activation and safety sensors for the common platforms, realign sweep angles to the entrance’s actual traffic, and test detection from every approach before leaving. Any brand, across the Klang Valley.
WhatsApp us what the door is doing — ignoring everyone, working intermittently, or only failing from one side — plus your location, and we will bring the likely parts on the first visit.