I live in SledgeTower and after initially working noise free, the hot water / heating system has started making a very loud buzzing noise when it turns on (see the video below). I'm guessing there might be air in the system...is bleeding the air out something I can do or should I contact Consult, or an Eon Engineer?
Well that doesn't sound healthy: Definitely needs looking at I would say. With regard who should do the looking, I would go for Barratt. The system that brings the hot water in to your flat, up to and including the heat exchanger unit and metering system are E.On's responsibility, the rest of it is Barratt (or so I believe). Sounds to me like a pump motor failing so would start with Barratt.