We live in the top-floor flat, in an old apartment building in Munich, which has communal heating. Every year around the start of 'autumn' (i.e., now) the heating system gets really noisy and starts emitting loud bangs/clunks throughout the day, and into the night. The noise comes from some (but not all) of the radiators, and in the walls (we assume heating pipes are there).
We assume the noise is caused by air in the heating system, but have never had this confirmed by the building owners. Last year the building management sent maintenance personnel round to us, after we complained (we had to wear ear plugs every night to sleep), but we were never told what the reason was. Eventually the noise went away by the time winter rolled round properly.
Does anyone know if:
1) this noise is normal for old heating systems, and we just have to put up with it? (I really hope not; we're again having to wear ear plugs to sleep)
2) if it's not normal, how do we get it fixed/improved?