strange sound coming from radiator.. fast constant drip

Billy March_2

Its probably expansion noise you are hearing. I'm surprised that it lasts for such a long time. Usually a pipe is resting against something (wood moulding ,riser pipe tight against the hole in the floor) but once the pipe or the radiator gets hot, the noise usually subsides. Alot of times you will hear the most noise in the morning if the heat was off while you were sleeping.

sreja

strange sound coming from radiator.. fast constant drip

one of the radiators in my apartment sometimes makes a very fast dripping sound when the valve is open.

nothing's dripping on the outside of it so the sound is coming from inside the radiator.

it also sounds much too fast to be actual "dripping" -- maybe 10 'ticks' per second? almost like a machine gun but doesn't sound violent like any kind of hammering, sometimes it's quite quiet.

lasts for hours, sometimes louder than other times.

radiator still gets plenty hot and haven't noticed anything unusual about it's performance.

i don't remember this happening before we did upgrades in the building and replaced the traps and valves on all of the radiators.

any theories about this mystery?

Brad White_191

Rapid-fire ticks

If it is a ticking sound and that rapid, a metallic sound, I think of sudden contraction such as steam going over a confined spot of water, rapid condensing or gurgling through that.

Does it sound like banging but on a much smaller scale?

Jamie Hall

I'd go with Billy on this one --

another possibility is the radiator itself expanding (I have a few which do that). It will just keep on going until the whole thing making the noise is hot -- then it may even, just to be perverse, start up again as the radiator (or pipe or wherever it's coming from) cools.

These can be the dickens to find, never mind get rid of.

sreja

i dont think it's expansion.. it's very very regular, almost like a very fast sped up clock ticking.. and its going on for hours at a time, at this regular rate, almost like a really quiet machine gun.

however i think i have a clue..

unlike all of the other radiators in the house, the inlet valve where steam enters is on the BOTTOM of the radiator, instead of the top. and when they did the work it seems like the heights of the radiators may have gotten shifted an 1/8 inch on either side randomly when they put in new fittings.

SO.. i'm thinking now that it must be steam coming in, maybe right on top of a small layer of water on the bottom of the radiator. Or something like that?

Possible?

Brad White_191

That is what

I think is happening. FWIW.

Big Ed_4

I don't know...

What is odd about this is the noise is rapid, constant and lasts for hours ? I never seen expantion or condening noise last for hours ? Maybe a minute....I am thinking sound transfer ???? But from what?

Any fan induced radiation in the building ?Condesate heating loop with a broken coupling on a B&G pump?

sreja

there is a condensate tank but it's 5 floors down and on the other side of the building, and it sure sounds like the tick is happening near the valve..

it could also be some flaw in the thermostatic valve i suppose.. but im thinking more and more that Brad White was right in his reply -- that because the steam valve is on the bottom, the steam must be coming in over a tiny puddle of water and boiling it.

Brad White_203

Or

collapsing the steam as it passes over it. I would check for "panting vents" to check this, just another view.

The Boiler Dr.

Does the radiator have

a TRV on it? It just might be the cartridge in the TRV bouncing or the TRV installed backwards.
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