CP - System boiler: Cylinder/tank temperature sensor faulty

What does CP mean?

This error occurs in system boilers when the cylinder or tank temperature sensor is not operating correctly. It could be due to a physical break, a short circuit in the sensor, or issues with its connection.

• Tank temperature sensor (NTC) is faulty (break or short circuit)
• Incorrect boiler type or soft code setting in service menu
• Damaged or short-circuited cables to the NTC sensor
• Defective electronic board (PCB)

Click steps to track your progress.

1. 1

   Switch off the boiler. Remove the tank NTC sensor from its terminal and measure its electrical resistance (in Ω). Compare the value to the NTC tables in the manual. If incorrect, replace the sensor.

2. 2

   Check the soft code and boiler type via Service function E.1 and 4.E. If the settings are incorrect, adjust them to the right boiler type code.

3. 3

   Inspect the NTC cables for any damages, short circuits, or breaks. If damaged, replace the cable or the NTC sensor.

4. 4

   If the issue persists after checking the sensor, cables, and settings, the electronic board (PCB) might be defective. Turn off the boiler and cut the main voltage supply before any further action.