Chamberlain Opener Error Code 1 flash: Meaning and Fix
Also shown as: One flash, LED blinks once
Reading the opener display
A garage door opener reports faults through blinking LEDs on the motor head, a diagnostic window on the logic board, or the wall control. Count the flashes slowly and repeat the count before you decide what you saw. Chamberlain boards use the same flash chart as LiftMaster; the Learn button color matters.
Chamberlain makes the openers sold at home centers and shares its logic boards and diagnostic code tables with LiftMaster and Craftsman. The faults show as a flash count on the Learn LED or the motor-head display. The codes apply to model numbers such as B4505T and B2212T; check the label on your unit to confirm yours.
What causes 1 flash
- A cut or loose sensor wire
- Staple damage
- Missing sensor
- Loose terminal
How to fix it
- Check both sensors have power lights.
- Trace the wire.
- Reseat terminals.
- Repair damage.
- Test.
Parts you may need
| Part | Part no. | Buy |
|---|---|---|
| Safety sensor kit | 041A5034 | Find part |
Part numbers are OEM references; confirm fit by your model number before ordering. Some links are affiliate links; we may earn a commission at no extra cost to you.
Questions
What does one flash mean on Chamberlain?
A broken or disconnected sensor wire.
Door will not close?
Yes, until the wire is fixed.
Which wire?
Check the pair from the opener to each sensor.
Other Chamberlain opener codes
Sources
Part numbers are OEM references; confirm fit by your model number before ordering. Meanings compiled from manufacturer and parts-retailer documentation; see sources below. Unplug the appliance before opening it.
Applies to models including B4505T, B2212T, B6713T, B2202T, C2405T, RJO20.