Aquapure 1400

I have an Aquapure 1400. I am receiving code 123 low current at cell. I checked the power cord and cell neither seemed to be correded or in any way bad.

I replaced the unit with a new one which I purchased fromn your store a few days ago. I replaced the cell and power cord not the sensor as my old one was fairly new and was not indicated as bad by any codes.

The problem is I am still receiving the trouble code 123. What is the next step as both the cell and cord have been replaced?

Paul