Since the early 90s, every opener sold has photo-eye sensors near the floor on both sides of the door. If their beam is interrupted - or they just think it is - the door refuses to close, or starts down and reverses. That’s the door doing its job. The trick is figuring out what it’s reacting to.

First: does it close if you hold the wall button?

Holding the wall button down (not tapping - holding until the door hits the floor) bypasses the sensors. If that closes the door, you’ve confirmed it: the problem is the sensors, not the door. Don’t make the hold-to-close move your permanent workaround though - the sensors exist for kids, pets, and bumpers, and un-bypassing them is a five-minute fix.

Check the sensor lights

Each sensor has an indicator light. On most brands, one is a steady power light and the other glows steady when the two are aligned. Blinking or dark = the beam is broken. Three causes cover nearly every case:

  • Something’s in the beam. A rake handle, a trash can moved for the week, a leaf pile. The beam sits inches off the floor and catches things you’d never think of.
  • A lens is dirty or webbed over. Garages here collect dust from gravel drives and pollen in the spring; spiders love the bracket. Wipe both lenses with a soft cloth.
  • A bracket got kicked. The sensors bolt to flimsy brackets at shin height. One bump from a mower deck and they’re aimed at the floor. Bend or loosen-and-reaim until the indicator goes steady.

One genuinely local quirk: on west-facing garages, low afternoon sun can flood a sensor lens and break the beam. If your door only misbehaves on sunny evenings, that’s the culprit - shade the lens or swap the sensors side to side so the receiver faces away from the sun.

If the sensors check out

Door starts down, touches something, and comes back up: the close force or travel limit has drifted - the door thinks the floor is an obstruction. These are the adjustment dials on the motor unit, and while the manual covers them, misadjusted force limits are how doors end up crushing weatherstrip or reversing forever. This is honest opener service call territory: $95-$250.

Door binds partway down, or sits crooked: look at the tracks and rollers. A bent track section or a roller jumping its track will stop a door cold, and forcing it makes everything worse - that’s an off-track repair, typically $125-$300, and it’s one to stop using the door for.

Grinding, straining, or a door that slams: have the balance checked. A failing spring shows up first as a door that closes too fast or an opener that struggles - catching it before the bang is cheaper than after.

The honest bottom line

Most won’t-close calls we could have talked the homeowner through for free - and we’re happy to. Describe what the lights are doing and whether hold-to-close works, and we’ll tell you on the phone whether this is a wipe-the-lens fix or a real repair with a real written price.