I just added a radiator (steam) to my kitchen and since then most of the other radiators in the house and banging and almost shaking. The steam valves seem to be working - at least steam is being released. As well, the water is draining very quickly. I keep the water level in the sight glass at about 2/3. Any suggestions - the plumber who did the job says the steam valves in hte other radiators need to be relplaced, but they seem to be working to me.