semiatic

LiftMaster garage door opener: Learn button LED flashes once

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Our drawing: the LED beside the Learn button, one flash, repeating.

A safety-sensor problem that stops the door closing: a sensor wire is broken or disconnected.

Applies to: LiftMaster and Chamberlain openers without UP and DOWN arrows, which flash the LED beside the Learn button. What you see: the LED beside the Learn button, one flash, repeating.

Covers Chamberlain openers too: the two brands share one published table, so each code has one page here.

What LiftMaster says to do

This is a safety-sensor code. The sensors stop the door closing on a person, a pet or a car. semiatic repeats only LiftMaster’s own alignment and cleaning steps; nothing here tells you to work around the sensors, and LiftMaster’s wiring checks are on its own page.

  1. LiftMaster says to clean the sensor lenses.
  2. LiftMaster says to realign the sensors until their lights glow steadily, and make sure the door track they are mounted on is secure.

LiftMaster’s page also has you look for a break or short in the sensor wires, behind walls and at the opener.

LiftMaster’s safety line: “Never adjust or loosen the door’s springs, cables, pulleys, or brackets yourself, they’re under extreme tension.” Where a spring, cable or balance problem shows up, its page says to stop and contact a local garage door professional.

No repair advice of our own. The steps above are only LiftMaster’s, as its page states them; semiatic gives no repair instructions of its own. For anything beyond them, LiftMaster’s page and a trained door technician are the authority.

Source

LiftMaster’s own help page, read on the date shown.

The same count on other openers

The same number of flashes on another maker’s opener means something else.

Other LiftMaster codes

Find a code by which light flashes and how many times, on any maker’s opener →