Hello, thanks in advance for your thoughts. Context
: I'm on the 1st floor of an old NYC building with single pipe steam radiator. Incident:
The bedroom radiator air vent (not the bullet/Hoffman kind) was making a high-pitched hiss for a while. The radiators/pipes were not making any other bangs or similar noises. Very stupidly (I still feel like an idiot), I tried putting a tiny wad of toilet paper just outside the hole to baffle the hiss. It worked but a few minutes later I saw it got sucked in a bit into the hole (didn't go in) and the vent was very hot. I took it out but since then, banging started coming both during heating and cooling. When heating would start, there would be near-constant bangs coming from underneath the radiator (I think) that would rattle the woodfloor, lasting most of the heating period. Then the entire time it was cooling, every 2 minutes there would be bangs originating from underneath as well. Closing the valve completely stopped the heating banging but had no effect on the cooling-period banging, so I opened the valve fully again. The livingroom-radiator is fine, no problems. Changes made and effects:
1) The super came in and first turned the boiler off and then on (in order to change the air vent to a Hoffman). This fixed the problem for 1 single cycle, then the same exact banging problem returned. It did fix the hissing problem fwiw.
2) He then pitched the radiator (see pictures attached). This fixed the problem PERFECTLY for 4-5 hours but over the past few days the banging has been slowly returning, which is odd. However: now, instead of the banging originating (seemingly) from under the floor, the bangs sound like they're coming from inside the radiator. And now its 4-5 bangs during heating, and also the same bang every 2 minutes during cooling. NOTE: The floor is higher on one side lengthwise, so now that it's pitched width-wise towards the boiler, the radiator is pitched slightly on two sides.
3) The super checked the pipes underneath the floor and reported no problems and no sagging.
Worth highlighting again that there were no problems at all with noise before I blocked the air vent for several minutes.Questions:
1) Ideas on how to proceed to fix? Why did pitching work temporarily but then stop working, and why did it move the banging from underneath to inside the radiator?
2) Is detaching and capping the radiator entirely a viable idea, would that definitely stop the banging? I don't actually need the heat from this radiator, the apt is hot.
3) Random - the super said he preferred the radiator valve be partially open. Everything I've read says it must be fully open or closed. Has anybody heard that sometimes it should be partially open? NOTE: I've left the valve fully open, but it hasn't lessened the banging.
Thanks so much for any thoughts, I'm at my wit's end and haven't slept well in a while. I'm not yet sure if the landlord is willing to hire a real plumber (hopefully yes) and the super only knows basic things. Please let me know if there is any info I left out, I'm very new to this.