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Whistling Radiator

I've been on quite the ride with the single pipe (this is when steam and water use the same pipe, correct?) steam radiators in my apartment. We've had a plumber here many times and it seems like the violent knocking that was the initial problem is finally resolved. The final step was to replace the air valves on our radiators since they were hissing. First, the plumber put on air valves that were very noisy, they were releasing way too much air intermittently once the radiators were warm. The plumber was finally back last night to replace these and now one is whistling until the radiators warm up. While the plumber was still here the heat was turned on twice and it didn't make this noise, it was about 12 hours later it started. In frustration in the middle of the night I was playing with it and noticed it was really loose so tightened the valve one full turn on the radiator by hand, was I supposed to do this? I realize now I probably shouldn't have done this while it was on, a large amount of water dripped out as I was turning it. When the plumber was here he did check the pressure on the system and turned it down, this was done before we tested the new valves. Unfortunately, I'm not sure we will get a plumber again, it was a struggle to get him out last night and the landlord tested the heat three times to make sure the issue was fixed before sending the plumber on his way because he doesn't want to pay a plumber again. Is there anything I can do on my end to make it stop?


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,564
    The job off the main vents is not only the release of air as the steam is rising, but also the allowing of air back into the pipes as the steam collapses into a vacuum at the end of firing. When the system has inadequate main venting, it can be quite a whistler on the rad vents, not only as the boiler first fires, but also when the air needs to come back in. There is more difference in pressure between a vacuum and atmospheric pressure than ever should be the case with a well sized boiler, pushing the air out as steam is being made.--NBC
  • Fred
    Fred Member Posts: 8,518
    You may never get a plumber back again but maybe this time ask the landlord for a Steam Pro. One that can check the steam mains in the basement annd determine where and how much Main venting the system needs to silence the radiators and also turn the pressure Cut-out down even more, if need be.
    That's about the only real fix we can offer here.