: Ensure the boiler is plugged into a 220–230V power supply. Check for a backlight or LCD display to confirm power.

An automatic 3-minute anti-cycling delay prevents the main burner from continuously cycling on and off, reducing component wear. Troubleshooting Common Error Codes & Reset Instructions

Wait for the unit to cool down. Check if radiator valves are open, then press . E03 Flue gas discharge or air pressure switch fault