CL - Hot water temperature sensor (DHW-NTC) is faulty

What does CL mean?

This error indicates that the hot water temperature sensor, which measures the domestic hot water temperature, is not functioning correctly. This could be due to a break, a short circuit, or incorrect resistance readings from the sensor.

• Hot water temperature sensor (DHW-NTC) is faulty (break or short circuit)
• Incorrect boiler type soft code setting in service menu
• Damaged cable harness connecting the sensor to the electronic board
• Defective electronic board (PCB)

Click steps to track your progress.

1. 1

   Switch off the boiler. Remove the DHW-NTC sensor socket 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 via Service function E.1. If the code is incorrect for your boiler type, correct it.

3. 3

   Inspect the cables connected to the DHW-NTC sensor for any visible damage, short circuits, or breaks. If damaged, the cable harness may need replacement.

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.