Help Identifying Sound from 2-Pipe Steam Radiator

shames

Hi everyone,

I have a 2-pipe steam heating system, and while most of my radiators are quiet, a few make a noise when they’re heating up. The sound seems to be louder near the top of the radiator. It’s not bothersome, but I want to make sure it’s not indicative of a leak or another issue. Note that I tried holding a small mirror near the area and I'm not seeing any signs of condensation or escaping steam.

Here's a recording of the sound to help identify it: https://drive.google.com/file/d/12GIWT-SXWQxs8Dk1P6kxyaT6w6edeiFD/view?usp=sharing

Does anyone know what might be causing this?

Thanks in advance for your insights!

Jamie Hall

Can't really make it out, but what I think I hear sounds more to me like a telegraphed sound from the boiler burner. You don't say what the boiler is, but either oil or a powered gas burner could make such a noise. Atmospheric wouldn't.

shames

https://forum.heatinghelp.com/discussion/comment/1827219#Comment_1827219

The boiler has gas burners; it's on the other side of the house and there are many other radiators closer to the boiler that don't make this sound.

ethicalpaul

Is it the high pitch squealing that sounds like subway tracks, or is it the low rumbling sound, or both?

shames

https://forum.heatinghelp.com/discussion/comment/1827234#Comment_1827234

To me, it's like a whistle but I guess I could see it described as a high pitch squeal. Could it indicate that it's leaking steam or maybe that the air isn't venting properly?

ethicalpaul

Is the supply valve partially closed? That is OK in a 2-pipe system but maybe it's set at a point that whistles?? Try opening or closing it more to see if the sound changes?

Do you have any knowledge of the typical pressure the system is running at, especially when it is making this noise?

If the steam were leaking you might see or hear it more obviously on the outside of the radiator I would think.

What about the low rumbly sound in the audio? Was that something else?

shames

https://forum.heatinghelp.com/discussion/comment/1827560#Comment_1827560

Sorry for the delay in my reply. The valves are completely open and adjusting them doesn't change the sound. I don't have a low pressure gauge (just the standard 1-30PSI) but the needle doesn't move much, maybe as a high as 1 or 2 PSI. The pressuretrols are set at the lowest they can go. If sound is pressure related, would I hear it on all of the radiators? Maybe not? I'm not sure what the low rumbling sound is; I actually didn't notice it until you said something.

ethicalpaul

It could be pressure related and only making sounds at that one radiator, but that’s not saying much since we don’t know the cause yet. Did I suggest temporarily removing or replacing the vent to see if things change?