Your boiler has stopped working because the water pressure inside the heating system has dropped too low.

System pressure too low. Compare to internal pressure dial max. 0.5 bar pressure differential between them. Top up water until the pre-set pressure reached. Intelligent filling loop 1. Switch off the intelligent fill in the system menu, re-pressurise manually and vent the system. 2. Ensure the correct pressure then factory rest appliance. If cause code does not clear power off appliance. Other filling loop Vent the heating system and top up water until the pre-set pressure reached. Pressure sensor 1. Check the continuity down harness for the pressure sensor and replace if required. 2. Check the voltage at the pressure sensor and replace if required.