Loud knocking noise in house with radiators and old plumbing
Even bleeding the systems won’t normally stop the clicking &amp; creaking as the pipes heat and cool the pipes expand and contract causing the majority of the noise, on steam systems there are DA tanks that remove the air , it sounds like normal expansion noise to me , I would not experiment at bleeding a system until I knew if it was a hot water or steam system. Most residential systems I have seen are hot water but I ran into a few low pressure steam systems in a high end neighborhood that we were installing gas furnaces. I thought only commercial was allowed live steam so I would be careful and probably get ear plugs.