Help, there's something vibrates in my CH system and It's driving me mad! It sounds like helicopters flying overhead and I'm sure the neighbours must be being disturbed by it. I've only recently moved into the house.When I had the [combi] boiler checked it was condemned in the first instance as it had been neglected for some time. That's now resolved, however, the pipes or something, vibrates something rotten when everything is off. It's not after things have just gone off either I've found that, even during the summer, when everything was switched off, it vibrates from around 11pm. It can be reduced by turning on the hot water but as soon as it's off, it goes again. Any ideas?