F.20 — Safety temperature limiter activated (NTC)

What does F.20 mean?

The boiler's safety temperature limiter has been activated by the flow NTC sensor. This typically happens if the sensor is not correctly detecting temperature or is defective, causing the appliance not to shut down properly.

• Flow NTC not correctly thermal-connected.
• Flow NTC defective.
• Boiler not shutting down correctly.

Click steps to track your progress.

1. 1

   Reset the boiler by pressing the reset button.

2. 2

   Ensure the system has adequate water pressure (check the pressure gauge).

3. 3

   If the error persists, contact a qualified service technician to check the flow NTC sensor and boiler operation.