How do I check the system pressure on my Greenstar 1000 boiler?

You can check the system pressure via the HMI screen by pressing the return button or navigation arrows to see the pressure display. The system pressure should be between 1.3 and 1.7 bar during operation, and between 1 and 1.5 bar when cold. If the pressure reads less than 0.8 bar, you need to re-charge the system using the external filling loop.