Remedy
System pressure is very or extremely low. This is triggered when the pressure falls to between 0.6 and 0.3 bar. Top up water until the target pressure is reached.
Intelligent filling loop
▶ Check in Main menu if Start filling option is available and select Yes option to start filling.
▶ If Start filling option not available, switch off the automatic filling function (Autom. filling > No) in the system menu, re-pressurise manually and vent the system.
▶ Ensure the correct pressure then factory reset appliance. If cause code does not clear, power off appliance.
Other filling loop
▶ Vent the heating system and top up water until the target pressure is reached.
Pressure sensor
▶ Check the continuity down harness for the pressure sensor and replace if required.
▶ Check the voltage at the pressure sensor and replace if required.