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New steam pipe LOUD BANGING!
I just finished a gut renovation of an apt in New York with a one-pipe steam radiator. The plumber had to replace a steam pipe that was leaking that went from the 6th floor to a small mezzanine/top floor. I know the plumber put in a slightly smaller pipe (3/4" ? instead of 1 1/4"?), but said that should be fine for a small mezzanine room. Now that the building heat is turned on, there is a ton of SUPER LOUD banging coming out of the radiator on the mezzanine every time the heat turns on. Wakes me up several times a night (and the neighbors, sometimes, too!). There is also an annoying tapping (almost like dripping sound) in the downstairs wall where this pipe was installed. The plumber insists that he didn't change the pitch. The upstairs radiator is sloped (slightly) towards the valve, which is 100% open. It is the same cast iron radiator that was in the room before, though it was kept in storage for a year while the apartment was renovated and the plumber installed a new valve and air vent.
Any thoughts on what we might be able to do to control the LOUD CLANGING sounds? The building has about 20 apartments, and my (top floor) apartment seems to be the biggest problem. I can ask the manager to bleed the system. Anything else they should try (adjust pressure, switch radiator?)