Apologies for late reply; I’ve been unwell. Many thanks for the replies to my original message.
I had the installer round this morning and he cleaned the system but now says the only thing he can think of is the gas pipe: it’s 15mm and hasn’t been upgraded and he didn’t upgrade it. Can that...
I got a brand new Worcester Bosch Greenstar 27Ri gas boiler installed in May and haven’t had any issues with it actually working, except since we started using it regularly we’ve noticed it seems to make a loud noise when igniting (I wouldn’t say like a bang but more like just a loud vibration)...