Do you have a good Power and Flow light?
Is the "Service" or "Add Salt" light on?
What are your %, salinity and temperature?
Try turning off the power for 1 minute and then restore power to see if you get "Cell On".
The AquaPure has a 3 hour cycle time. The percentage setting will control how much the cell runs during the cycle.
For example, at 50%, the box will say "Cell On" for 1.5 hours then "Cell Resting" for 1.5 hours. Then, there is a two minute off time, then the box will say Cell Reversing for 1.5 hours, then Cell Resting for 1.5 hours etc.