My ClearBlue Ionzier controller says ‘PL’. What does this mean?

PL Stands for Program Lock

If you see ‘PL’ on your ClearBlue or Mineral Lion controller, it means the controller is locked. Hold down the Up and Down arrows together for 30+ seconds until the screen changes to a number.

To lock the settings again after you have reset them, hold the Up and Down arrows down for 30+ seconds until the screen changes to ‘PL’.