Troubleshooting iSipool PH L3 Sensor Issues: A Client-Advisor Dialogue

Client:
Is this still available?

Technical Advisor:
Yes, it is.

Client:
It doesn't work on the iSipool PH L3. I tried 3 sensors but they don't work. The old one works but it's too old and I sent it back.

Technical Advisor:
Hello. Yes, it does work on the iSipool PH L3. But we sell many of them. Can you describe the trouble? First, test your probe like this https://ph-redox-pool.com/gb/content/16-ma-sonde-ph-est-elle-hors-service-. Our warranty is here https://ph-redox-pool.com/gb/content/15-compatible-or-refunded.

Client:
If I calibrate a new sensor it works well but in run mode the red light burns and CE is on the screen. I did the test with PH4 and PH7 as in the description but new sensors don't work, only the old one. I've tried it with water and vinegar but in normal mode it still shows CE 2.4 with the new sensors. That's why I'd like to order.

Technical Advisor:
2.4 is not normal, the probe is out of order.