Hi,
The CircuPool techs are available six days a week; give us a call when you are at the unit and we will quickly determine the cause. One thing to check first is where the electrical cord plugs in the cell. Make sure the blue wire is on the middle terminal and that all three electrical cell connections are clean and tight. Lastly, if your pool water is below 50 degrees, the readings will not be accurate until things warm up.
Thanks,
Don
936-372-1515