Very strange whistling radiators problem

sreja

It's been a long time since I posted.. Encountered a very strange problem in my apartment the last 2 days.

Background: I am in a 5 story TWO-PIPE steam heat condo, with TRVs on each radiator. I am the one who has managed the boiler over the last 8 years or so.

So here's the problem -- I started hearing a constant whistle a few days ago.. Which has gotten louder over the last couple of days.

It's a little hard to pinpoint the source of the whistle but it SEEMS to me to be coming near the top where the TRV is.

BUT here is where it gets reallllly strange. Today I believe the whistle is happening on BOTH this dining room radiator, AND the one in the room next door now. BOTH seem to be whistling. I am flumoxed to figure out how this could be...

More strangeness: Turning on or off the valve does *NOT* effect the whistle. Neither does my attempt to put a towel over different areas to try to find where the sound is coming from by dampening different areas..

I am at a loss to explain these symptoms.

Both radiators are fed from a common supply line under the floor. The only thing I can think of is that there is some leak in the supply line causing the whistles and that somehow even though it sounds to me when I put my ear up against the radiators that the sound is localized near the inlet pipe, that really the "source" of the whistling is the common supply line under the floor a few feet away?

Or is it somehow possible that TWO radiators are suddenly whistling at the same time after 8 years of nothing?

Anyone have any theories?

To recap some basic stats:
1. Two-pipe steam
2. TRVs on both radiators, both supplied from same supply ine
3. Boiler pressure is good, under 2.5 pounds
4. Traps and TRVs are about 8 years old.
5. Problem just started a few days ago -- started out quieter and only in one room, now louder and more constant and seeming to come from 2 dif radiators..

Feel like I am losing my mind...

JUGHNE

Has the pigtail been cleaned? A partial plugged pigtail can fool both the control and gauge.

EBEBRATT-Ed

Try closing the radiator valve just to see if the whistling stops. Check the boiler pressure and pigtail under all controls

sreja

"Try closing the radiator valve just to see if the whistling stops."

Yeah that's another part that's confusing me.. Closing the TRV valve has no effect on the whistle..

I should say, I don't know if whistle is the right word.. it's sort of a whistle, sort of a whine..

Intplm.

@sreja you might have a leak somewhere and it is resonating in that area of the house. This type of noise can sometimes sound like it is near the rads but is farther away. So no, you are not losing your mind.👍
Do what @JUGHNE and @EBEBRATT-Ed suggest, and go from there.

Jamie Hall

Is the TRV on the inlet? For one pipe steam it should be a TR VENT, and there should be another, hand valve, on the inlet. If there is, try closing that one (don't leave it closed -- leave it fully open)

Fred

Are you sure steam isn't leaking past a closed TRV? It may have dirt or something in it preventing it from fully closing.

sreja

I've played around with the TRV and valves and all areas of the radiator, putting heavy covering over it, etc.. And the sound is unchanged/undiminished.. That's partly what's confusing me.. It's like a ventriliquist act, the sound appears to be coming from a place but is not behaving as if it is.

Intplm.

You might just possibly have a leak that is making the noise.Its throwing its voice or acting like a ventriloquist? Probably a leak that is not on the radiators. Possibly near or between the two radiators. "A Whistle" a little like from a "steam locomotives" steam whistle.

JUGHNE

STeam in the return line from a failed trap?
Could close other traps then TRV closes creating vacuum in rad?

Dave in QCA

Are there TRVs on all of the radiator valves in the building, or just yours? Does the sound continue even when the boiler is off? When you experiment with closing the valve all the way, did you close both of the valves all the way? You said that they were both connected to the same riser, if I understood correctly.

sreja

TRVs in entire building; sound only happens when the boiler is on. I will try double check that closing both TRVs does not affect the sound. Yes both radiators supply come off the same T.

sreja

Confirmed no change in whistle even if both TRVs are off.