Steam radiators clicking when heating comes on

anatori25 · March 2023

https://youtu.be/zTSkpVrV_PE

https://youtu.be/LagT3OlGahA

Hello Everyone,

I am very glad to finally find your website!

I live in a coop in Queens, NY, top floor of 6-story apartment building built in 1938 and converted to coop in 1980s. The heating system is original from 1930s, one-pipe steam with cast iron steam radiators inside metal boxes recessed in walls. I've been living here for 4 years, and when moving in, I made some renovation, but left the radiators as is (just cleaning, repainting panels and installing decorative panels). When heating season started, I immideately noticed the banging/clicking noice coming from one of two radiators in my living room. I was able to locate the problem - in 80+ years shut off valve's stem corroded and lower metal part (gasket?) was flipping inside the bottom of the valve blocking steam/water and making all this noise. Super helped me to replace the valve and the noise stopped. The next season the next radiator in the same room started banging every time when boiler kicked on (specially early in the morning). You could here and trace this banging noise coming from 2-3 floor below with final BANG on my floor. Interestingly, the noise itself started not when heat comes in, but several minutes earlier, when cold air start moving out of air valve. In a couple of months the pipes "settled in" and the rest of the season was quite. This season the very same radiator showed different behaviour, though… I realized that like many buildings in my neigborhood my building "slided" a little bit downhill (it is quite noticeable in my apartment) and radiators (at least some of them) were not level any more. And, the original installers used support rods, but some are missing or were not installer in the first place - their number is different in different radiators - 2-3 (not 4). May be, in a long run it caused the misalighment as well. So, I tilted thet particular radiator (see attached picture2) towards the shut off valve. Then, my problem instead of banging was clicking, very loud. This time it is strictly when the steam (not cold air) is coming into the radiator. After some experimenting with tilt I had to shut the radiator down completely (removing air valve and pluggint the hole). But a previously silent radiator in my bedroom started to do some clicking also (picture1). So, now I have completely unpredictable alarm clock in my bedroom as well…I understand, as some experts here mentioned, that this clicking is related to expansion, and may be, the cause is "tie rods" on top and in the bottom of the radiator or metal plates in tie rod assemblies (I am not sure what role these plates play).
I would really appreciate your advice, esteemed experts! In spite that fact that radiators are technically inside the walls, my coop board says that dealing with radiators is a shareholder's responsibility, so I am on my own. I called a couple of plumbers in my area, but they are generally not interested in dealing with coops and old radiators..

ethicalpaul · March 2023

That is a massive wall of text 😅

I know this isn't today's question, but what you get in return for posting a lot of old unrelated details is that sometimes people pick something out of there to comment on, and today is that day 😉

You could here and trace this banging noise coming from 2-3 floor below with final BANG on my floor. Interestingly, the noise itself started not when heat comes in, but several minutes earlier, when cold air start moving out of air valve.

Somewhere below you there is a settled pipe, or mis-laid pipe that has a low spot where water settles, and on the next heating cycle when steam hits the cold water, it causes water hammer. So that's probably the explanation for that issue.

For your actual question, I don't have a good answer. I have a traditional radiator that does this clicking, and it is almost certainly expansion of one part or section rubbing against an adjacent section. You can mess with the rods a little bit or even maybe try some kind of lubricant, but I think your odds of success are rather low.

You can plumb a valve in line with the vent and turn off the valve when you go to bed and that should prevent that radiator/convector from getting any steam until you open the valve back up, that's probably the direction I would go.

anatori25 · March 2023

Thank you Paul!

My first assumption was that may be some part of old gasket entered the radiator causing this metal click, but alas expansion is the most (as I understood) difficult to deal with. For now the only remedy is what you adviced. I still don't understand why they put metal plates on tie rods. Can I remove them trying to figure out if they contributing the noise?

Thank you again!!!

ethicalpaul · March 2023

I looked again and that sound could still be small water hammer in your convector. The challenge is that both water hammer and expansion clicks happen as the device is heating up so it makes it hard to figure out which it is.

I wouldn't remove them, but at least try to see if they are the things making the noise by keeping your hand on them during heatup to see if you can catch them making the noise. But again, this might be being generated from inside the convectors

anatori25 · March 2023

Thank you for quick response! Convector is the unit itself, right? I also noticed that in some sections adjacent rows (fins) touching each others while in others you can easily put in metal saw blade…Many times I tried to locate the noise, but it looked like it was originating from inside (not 100% sure).

Jamie Hall · March 2023

Nice units. However, you have a whole lot of little machnine screws and nuts holding them together. First thing I'd check would be if any of them are even a little bit loose. They shouldn't be — however, tightening them may not be possible; machine screws don't lend themselves to tightneing (or much of anything else) after sitting for years. But check. If you find some which are loose but can't tightne them, try getting some graphite lubricant in there (four contact surfaces on each on to lubricate).

anatori25 · March 2023

Thank you Jamie for you advice!

I will try to tighten them this weekend (actually, I already tried a couple of them, but was not sure how tight it should be). May be it will help to make the clicking go away!!

anatori25 · March 2023

One more question, Jamie

You mentioned machnine screws and nuts. Does it mean that is is all them holding radiator sections (units) together??? If so, it completely different from what I thought.

Jamie Hall · March 2023

Actually, without looking at it in person, I'm not sure whether those are holding it together — or just what they are doing. But they shouldn't be loose…

neilc · March 2023

guys, are we sure that's a water hammer I hear ticking in the videos?

are any of those cast fins touching the rear cover/case?

if so, try slipping some strips of plastic milk jug into the touch points

anatori25 · March 2023

Hi Neilc,

That was my assumption as well...I tightened all nuts/bolts yesterday, but clicking is still here on both radiators. I am trying to locate it, but no vibration, looks like the sound itself coming from inside the radiator. I have no idea about its internal structure. No indication of manufacturer except "37Y" in between some fins. I have no idea how to proceed, all ideas are very appreciated

ethicalpaul · March 2023

https://forum.heatinghelp.com/discussion/comment/1744367#Comment_1744367

I'm definitely not sure 😅

neilc · March 2023

that rad in the top pictures,

it looks like it's pitched excessively back to the supply and valve,

and that it's got a belly at the 90 at the floor,

maybe this is the hamma (?)

then I'm still looking at all those cast fins, and the assembleage,

if you look down thru the fins, one cast section to the next, are any of those fins ends touching their neighbors? click, click, click ?

or also, horizontally? touching? click, click, click ?

maybe you run a sawzall metal blade thru the fin(s) ends to create spacing??

At the top and bottom, between the sections, there are those different flat spreaders(?) that the many little connector machine screws go thru, are those spreaders wiggly loose in between the cast sections, click, click ?

when you're hearing the noise, and before the cast sections get steaming hot, can you touch any of these points and calm the clicking? or feel it at the floor 90 ?

anatori25 · March 2023

Hi neilc,

Thank you for your comments and advice!

I pitched it excessively on purpose as desperate attempt to "experiment", may be in the process messing it up more. So, the level (surface) of the radiator itself should be parallel to that angled pipe (belly?) near the shut off valve, right?

Regarding fins, yes, there are some sections where blade is stuck… Since the clicking noise is coming from "inside" the radiator (as it seems to me), may be this is the reason. And yes, some of the flat spreaders (no idea why are they here) are loose in spite of my attempts to thgihten the bolts (I am afraid to brake th ears, already broke one), but no obvious clicking noises so far from them. So what do you think, creating spacing should be my first priority?

Thank you

neilc · March 2023

I'm grasping at straws with the fins touching, and clicking with expansion,

but if you see some edges against eachother, and a way to get at them and releive some space for movement,

, , ,

I wouldn't worry bout the spacer plates if they don't seem to be the source of click, don't break any more casted tabs there

anatori25 · March 2023

Completely agree with you. Yesterday I adjusted pitch on both radiators. Based on information from this forum (you guys rock!) , I could identify my radiators as Arco convectors circa 1937 and even some its specs. So, for one pipe systems the manufacturer advised to pitch 1/8" for every foot of radiator lenth, which I did. As a result, the clicking is now more loud, but I am very positive that the source of it is fins touching each other when expanding. It turned out that radiator itself consist of several rows (3 in living room and 4 in bedroom) of convectors with fins and they are fixed together by left and right end plates(?) and then by spacer plates. Some rows are touching each other even in cool state…I tryed to insert a wedge (screwdriver), and the gap is flexible when some force applied. I plan to insert some shims (plastic strips) in tough places and if it would make any difference!

Hap_Hazzard · March 2023

https://forum.heatinghelp.com/discussion/comment/1744199#Comment_1744199

The thing I've noticed about expansion noises, be they sections in expanding radiators or risers rubbing against floorboards, is that they almost always happen when the system is heating up AND when it's cooling down. Whatever mechanical interference is happening while something is expanding almost always gets played in reverse when it cools down. It may not sound exactly the same, but usually similar. I've also found that, nine times out of ten, there's some tension left in a noisy radiator after it's completely cold, so if you go over and bump it, it'll give out one last "ping!"

anatori25 · March 2023

Hi Hap_Hazzard!

In my case, all this clicking noise is when heating up ONLY (stricktly speaking, when cooling down I can hear near this particular radiator very distant dull clicks like metronome). Based on assumption that it may be convector's fins rubbing each other I put yesterday some plastic between rows, but alas the noise is still here…Interestingly enough, in good radiators fins are touching each other as well, but no noise (fingers crossed). So, may be it is something else like nipple connection between sections. If so, what are my options? remove and replace the radiator?

Hap_Hazzard · March 2023

As long as it's making heat and not leaking, no need to do anything drastic. Until you isolate the source of the noise, you can't be sure a new radiator won't make the same noise in the same circumstances.

Looking at the pictures, it looks like you might have gone a little too far on the slant. Because the supply pipe has a short horizontal run that goes opposite to the slope of the radiator, some water will remain in the elbow fitting. While it's not long enough to create differential shock, it can cause the steam to contract suddenly when it reaches the cold water. This will cause a cyclic banging noise because each time the steam builds up to the pooled water, it contracts again. The cycle repeats until the steam transfers enough heat to the water to evaporate it. At this point, the elbow will feel hot to the touch. You should also be able to hear air being sucked back into the vent every time the steam front collapses. Look for these symptoms and then try experimenting with the slant of the radiator and see if you can find a happy medium where not much water pools in the radiator or the elbow.

anatori25 · March 2023

Thank you again!
I already adjusted the pitch, but since the clicking is still here, I started to think that may be installing new cast iron radiator is the only option. I definetely hear water/steam(?) gurgling and will try to check the air being sucked back..and adjust the elbow.
Wow, what a complicated art is steam! I salute generations of engineers and technicians who made it work.

neilc · March 2023

if you're hearing gurgling,
then better go back and check that the valve disc(s) hasn't disconnected and is partially plugging the seat and or condensate returning,
another possibility, the vent may be too fast and is holding condensate back as air pushes to escape too fast.

anatori25 · April 2023

The valve was my first suspect when this heating season started. But in my particular case the valve is sitting right beneath the radiator, and to replace the valve you first need to disconnect the entire radiator and move it out of the metal cabinet. If I do so (which I am inclined to do after failing to address the clicking issue) , I will replace this monstrocity with something more simple. Anyway, I need to wait till building's heating season is over.

ChrisJ · April 2023

I may have missed it being mentioned but why isn't there a vent?

anatori25 · April 2023

Hi Chrisj,

I know it is stupid, but it was my way of turning off the radiator (the shut off valve is in fully open position and when I try to close it the steam is still entering the radiator). But to try different option I put the air valve back - whether it is Hoffman #40 or generic drum from Home Depot, the ckicking is still the same, and I am more convinced that the noise occuring inside the convector (between sections?). I am wondering if there is any way to treat it or my only option is to replace the radiator...

ChrisJ · April 2023

anatori25 said:
Hi Chrisj,

I know it is stupid, but it was my way of turning off the radiator (the shut off valve is in fully open position and when I try to close it the steam is still entering the radiator). But to try different option I put the air valve back - whether it is Hoffman #40 or generic drum from Home Depot, the ckicking is still the same, and I am more convinced that the noise occuring inside the convector (between sections?). I am wondering if there is any way to treat it or my only option is to replace the radiator...

That's not stupid just be careful that bolt doesn't booger up the threads.
I think 1/8" NPT is 27 threads per inch so nothing is really going to match well.

mattmia2 · April 2023

The noise is very likely water trapped in that pipe that goes down hill between the valve and the radiator. You may need to raise both ends then give just the slightest pitch toward the valve(you also may need to do something more creative if the spud out of the valve is still sloping downhill after you adjust the pitch of the convector element). Are you sure the new valve you used is a steam valve? The valve must be all the way open(I think you now this but just to be safe). It also could be water trapped in the runout below the floor, that could have dropped in your attempt to give the convector element pitch or when the valve was changed.

Changing to something other than a convector with a cast iron element wouldn't be a good idea. It would heat differently than the rest of the system and would be difficult to impossible to balance.

There are ways you can connect the end opposite the supply to a return and slope it that way and drain the condensate back to the supply below the convector connection, that may be a last resort solution.

anatori25 · April 2023

Thank you mattmia2!

I will try to raise both end! The valve side rod is not moving, so I will cut it as I did to the other side...I am also very interested in your "last resort" solution, but I am not sure that I understand. Can you please provide some details?

Thank you in advance,

mattmia2 · April 2023

Some of the other people that know steam really well can give the solution to supply it at one end and drain it at the other, but look for ways that baseboard radiators can be hooked up as 2 pipe on a 1 pipe system, there are ways to do it without getting below the floor, especially when you have space to raise everything up in the convector cabinet a few inches.

Instead of trying to turn the rods if they are frozen I would put shims under it, at least for testing.

Steam radiators clicking when heating comes on

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