!!
critical Garrison
Error Code Red LED flashes with beeps, one quick beep every 30 seconds
Indicates an error condition detected by the unit.
? What Causes This
Internal fault or malfunction detected by the diagnostic system of CO alarm.
✓ How to Fix It
Replace the CO alarm immediately, as it will not respond to CO while in this state.
Source: page 13 of the official manual
From the manual
This error code appears in:
Garrison 043 6119 2