!!
critical Orbit
Error Code NO AC
There has been a power failure and no watering will occur.
? What Causes This
Loss of AC power to the device.
✓ How to Fix It
Restore power by ensuring the timer is connected to a working electrical outlet or that the circuit breaker is turned on.
Source: page 15 of the official manual
From the manual
This error code appears in:
Orbit 27894 Sprinkler Timer