I bled top floor house radiators as they were making a lot of noise - then added water via filling loop, but gauge remained at 0.4 bar, despite tapping it. Eventually after c 15 seconds of filing I heard 'knocking' in the boiler, which I presume was the prv letting off ( although i don't know where this releases to). My question is - is it likely the pressure gauge is broken - and if so can I test/ replace it.?
Any advice appreciated.
Any advice appreciated.