Hi, my son and his partner have just moved into a property where a Glowworm Flexicom 30cx is currently installed. They've already had an instance of the F.22 (low pressure) fault code and indeed the underlying pressure is showing as just 0.5 bar. I pressed the reset button and it seemed to bring the boiler 'back to life'. Question: does this boiler have an integral/built-in filling loop through which I can introduce some more water to up the pressure? Hope someone can help on this, thanks