What does NO AC error mean on the 27894 timer display?
A 'NO AC' display indicates that there has been a power failure. No watering will occur when this error is displayed. Once power is restored, the timer should resume normal operation. If you have a battery installed, your program will be retained in memory during the power loss.
From the official Orbit 27894 Sprinkler Timer manual, page 14
Have a follow-up question?
Answers from the official manual.
Common questions