How do I re-pressurise the heating system using the external filling loop?

Attach the filling hose to the valve, ensure both ends are hand tight, then turn the isolation valve handles 90° to open them and slowly fill the system to between 1 and 1.5 bar. Once the correct pressure is reached, turn the handles back 90° to close the valves, then remove the hose and replace the blanking cap. You must disconnect the external filling loop after re-pressurisation to comply with Water Authority regulations. (Page 8)