Repressurising Logic Combi 24 boiler
So I got a guy out to fix it. This was months ago at this point. However, he discovered that the fill loop had been put on "the wrong way around". I'm not a plumber, or person who knows about pipes, but I am assuming from his explanation that water simply couldn't flow either way through this small section of pipe... regardless, he said he put it on the right way around, and indeed I can now repressurise the system. I have no idea why the guy before this put the pipe on backwards..