Water Hammer in 2 out of 4 radiators in a co-op unit. How to fix it?

coophammer

Hello all - I'm hoping I can get some guidance here... I've spoken to one member of the forum who was helpful, and hoping for some extra input among the group.

First the backstory:
- Building is a 65 year old co-op with single pipe steam heating
- I lived in a different unit, on the 1st floor, for 4 years, and never had water hammer there
- I moved upstairs to the 2nd floor, and now I hear this awful water hammer in 2 of my 4 rooms.
- Thinking it was because water was stuck in the radiator/pipes, we drained the pipes yesterday. There was a lot of water in one of the pipes because I had the valve half open, and maybe closed the valve when the pipes weren't cold, previously.
- The 2nd room, however had completely open pipes, and was still banging. Super thought that maybe the banging was from the pipe with water, and was being heard in both rooms.
- So now both pipes are bone dry, after draining...
- And there is loud water hammer the very next day.

So - my question is - why is there water hammer? If my rooms have water hammer, should that mean that the unit below me has it also? And that the units above me also have it? Could there be water in between the 1st and 2nd floor unit which is causing it, and is not easily accessible? Could it be a boiler issue? (I would think if it's a boiler issue, then every floor would suffer from the water hammer, right?)

Looking forward to your ideas and tips.

dave_myrick66

It sounds to me as if the radiators are holding water. Are there air vents on the radiators? If they are there, are they working properly? If the vents are clogged or otherwise not allowing air to enter the radiator during the off steam cycle, a vacuum can form in the radiator and besides not heating well, can possibly cause water hammer.

coophammer

Hi Dave, thanks for the comment.

The air vent on bedroom (with the half open valve) had water, as it should have, because the pipes had water.

The air vent in the office did not have water... or maybe just a few drops, which is considered normal...

But bottom line is the radiators are both banging loud and clear the next morning...

So I would think this is not an air vent issue... but I can double check. (But I don't think it is.)

coophammer

I should also note that bedroom radiator valve is currently closed. So there shouldn't be heat hitting water in there and slamming it around, right?

KC_Jones

First, the valves on a one pipe steam system should stay fully open always. Second anything that is full of water is wrong, this indicates improper pitch on a pipe or a radiator. Steam pipes should essentially be empty when you open them up. Perhaps a few spoonfuls of residual water "sticking" to pipe walls or laying in fittings, but basically empty.

Water hammer is the steam picking up water laying somewhere and slamming it into a fitting at relatively high velocity. You have water laying in a pipe or in your radiator and that is causing the problem.

The reason it started back up is because after the system ran and condensed a bunch of steam back into water, the pipes/rads filled back up. There is a pitch issue or a sag somewhere andyou need to locate it.

coophammer

KC Thanks for the added input. I think my wife and I would overheat if we left the bedroom valve open all the time. It gets uncomfortably hot (not to mention also a little odorous) in the room, so I'd prefer to have no heat in there, if I can choose.

The fact that I don't have any water hammer in the kitchen or living room makes me think that based on your idea - that there a pipe below my unit that has water in it for some reason.

However that also doesn't make much sense, because the super tells me that it's a vertical pipe connecting my downstairs neighbors to me..

So would this mean my neighbors must be suffering from the same water hammer, and if they are not, then it has to be water in between our units somewhere?

Gsmith

As KC says, the valves to the radiator should be open all the way at all times (except maybe if you remove a radiator for maintenance for example). You can control the heat the radiator gives off by limiting or stopping the air from getting out the mid-height air vent on the side of the radiator opposite the steam inlet pipe.

If you want to test this, at some time the boiler is not running (steam is not being produced), take off the air vents on the radiators which are banging, shake them off and then either plug the holes with a 1/8" diameter brass or steel plug, or for a short time only turn the air vent valves upside down. See if that eliminates the banging. this will also eliminate steam from getting into the radiator and eliminate heat coming off the radiator. If this works, consider getting a slow or adjustable air vent for these two radiators (like the vent rite #1 adjustable vent: http://www.hvacrsupplynow.com/VENT-RITE-1-STEAM-AIR-VALVES-ADJUSTABLE_p_1787.html), so you can adjust the air getting out and the heat given off by the radiator without restricting the condensed water from leaving the radiator. Of course the radiator must slope slightly TOWARD the inlet pipe and supply valve.

coophammer

Gary, I thought that based on what I've read, the valve should be either completely open or completely closed. Is this not correct?

Thanks for this new idea about plugging the air valve. I did not consider that was an option. I will head to the hardware store and see if I can pick up a plug.

You mention turning the air valve upside down, but it screws in vertically to my unit. So I don't think that's possible. I'll attach a photo to better explain:



Do you still think the air valve could be the issue?

coophammer

I should also add - this radiator, which is in bedroom 2, knocks loudly, and has a fully open valve. (The thing at the bottom, not the silver air valve, which I haven't touched)

Fred

Looking at you picture, I see a reducing elbow (I think) where the larger end is connected to the convector and the smaller end is connected to the nipple to the supply valve. I would guess that bowl in the elbow holds some water before the level raises enough to reach the level of the smaller pipe where it can drain.
You can either replace the supply valve with a larger valve (the same size as the pipe connected to the convector) and bush the valve down where it mounts onto the pipe coming out of the floor or, if you can get that nipple out of the convector, you can bush the opening into the convector and use a pipe the same size as the nipple going into the supply valve.

coophammer

Hi Fred thanks for the input. There are a lot of terms there that I had to look up - but if I'm understanding correctly, you're saying you would need to adjust the size of the connectors/piping. It's a bit over my head... but I'm wondering why if this is the problem, it's not happening in the other rooms.

Gsmith

Yes, the valve at the bottom should be fully open. I see from the picture (as always worth a thousand words) that you cannot turn the air vent upside down with that type of air vent. so if you want to stop the heat completely you can replace the air vent with a plug--of course no heat will come from this radiator.

See @Fred's comments about possible corrections to the pipiing, I agree with him. Can you also check the slope of the short pipe between the supply valve and the 90 degree elbow to make sure it slopes downward toward the supply valve, it looks like it does, but sometimes it's deceiving.

And, you might consider repiping that valve and radiator, the valve acutally looks like it is reversed and the valve seat may be holding water back in the short horizontal pipe since the valve seat (where the disk goes against in the closed position) is smaller in diameter than the inside of the valve or the pipe to the radiator. Most radiator valves are mounted so that the valve stem (attached below the black knob) is in the vertical position. It looks like you have room to raise the fin-tube pipe and put a normally oriented valve and pipe connection to the fin-tube.

Gsmith

You might also try lowering the slope of the fin tube part, where the plywood is wedged in, to give a little more slope to the short pipe between 90 deg elbow and valve while still providing slope on the fin tube portion. Maybe the plywood is wedged to make the fin tube slope too great and creating not enough slope in the short pipe section.

coophammer

Thanks @Gary Smith - I inspected the short pipe closer and I'd say it's lying pretty flat, if anything. As far as re-piping like you are stating, and as Frank had stated - if that's the issue, shouldn't all of my heaters be banging? Would I be wrong in assuming that? Because I have 2 other radiators with the same set-up, and they do not bang.

I was also wondering - if I can listen closely to where the banging is occuring would that help? If I could put my ear to the ground and here it rumbling and banging beneath the floor boards, would that mean the problem is not on my floor, but below it?

Fred

@coophammer , I really can't speak to the other rads, if they are piped exactly like this one. Some times things work, other times they simply don't. Best practice, especially for steam, if you have to reduce the size of a pipe or valve, the reduction should be on the vertical pipe not the horizontal. A horizontal reduction will allow water to pool, which is what causes hammer. Double check those other convectors and see if there is a reduction in the pipe to each of them and if so, if it's on the vertical pipe (which is fine) or on the horizontal.

Gary, I think his valve configuration is Ok. It's an angle valve and it should not be a problem.

Kahooli

*IANAP*
Don't forget, water hammer could be water at the bottom of the riser being shoved up through and banging into your 90 valve. The noise is at your rad, but the pooling condensate could be in the basement.
You could carefully raise both the rad and riser pipe a bit if it moves freely. Might cause a leak doing it though...

coophammer

@Kahooli , thanks - I have a feeling, though I'm no pro, that the water is collecting between my 2nd floor unit and the 1st floor unit below. Not sure where though, because the Super says that there is a vertical steam pipe connecting the 1st floor unit to mine...

MilanD

All those risers generally have horizontal swing joints, 2 ells and a pipe inside the joist space - below your floor and above the downstairs ceiling, to allow for pipe expansion. Pooling of condensate can happen anywhere in that horizontal section, including the ells. Hammer can happen in 2 ways: at startup with steam collapsing against the cold water sitting in the pipe or the fitting, or steam picking up water and banging it against an ell. Essentially, any horizontal run can sag or drop down and pitch the pipe opposite of the draining pitch and hold water. This sag can be from overall building settling, floors sagging...

The trick is finding it. Ask your neighbor below and above, if they too can hear your rad banging. If not, your sag may be in the swing joint ell just below your radiator and your recourse is to raise your valve end by 1/4 or 1/2 inch... fulcrum and a lever. Your convector is also pitched quite a bit so you may not jave to worry about raising the vent side. If they can hear it, it may be closer to the vertical rad riser, and you may have to raise that convector even more. This may not be that easy.

Best of luck!

Fred

@coophammer , I keep looking at that convector in your picture. One other thing to try that won't cost you anything. Lower the high end of that convector so that it only has about a half inch of pitch back towards the supply pipe. There is a good possibility that that convector is condensing fast enough that it produces a lot of water and, with that pitch, that water races back to the supply end of the convector and actually shoots right into the the flow of steam coming up that vertical pipe causing the hammer. Lower the pitch, slow the flow of condensate to where it drops down around the inside edge of the pipe.

coophammer

Hi @Fred @MilanD and others - I just wanted to update you guys.
The building management sent in a different plumber who replaced the heating element, and replaced the air valve, but the new heating element has a terrible smell near the piping of the element (not the coils) (I wrote another discussion about this...)

and so - I ended up closing the steam valve completely - and the knocking didn't change. Perhaps it got a *little* less loud, because the plumber tried grabbing and lifting the piping coming through the floor...

Also - my super tells me that *no one else* in the building is complaining about water hammer... including my top and bottom neighbors, so what this tells me, is that there is probably water pooled in an ell joint *under* the floorboards...

and I think the only way to correct it would be to use the fulcrum as someone stated, and raise those pipes way up, or to break open the floor to do so.

However I'm concerned that this is a costly, messy procedure that might not even fix the problem.

My most pressing problem is now the bad smell of this relatively new heating element.

KC_Jones

Where are you located? We may know someone competent in your area that can take a look and figure it out.

Replacing the emitter isn't going to fix a water hammer issue. That shows me that contractor doesn't understand steam.

As long as he does "something" someone is happy they are trying. You pay them to fix it not guess.

Again water is laying somewhere and being picked up by the steam and being slammed around.

Lack of complaints isn't a solid matrix to me. Some people think steam makes noise and just accept it, they system should be completely silent at all times.

Have you asked the neighbors if it's silent?

coophammer

@KC_Jones located in brooklyn NY. Problem is that this foolish management company only uses their guys, when I mentioned bringing a specialist in, who I had researched, they said "they don't hire people off the street." ... ridiculous.

I did ask the neighbors to the side of me and they don't have the problem.

KC_Jones

Ask them if they want to hire quality?
Ask them is they like flushing money down the drain.
Ask them if they want you to go away and stop bothering them.
Also isn't it technically your money that is paying? I'd stop paying until they listened, no one owns me. I know that's a strong opinion, but to me that is the reality they are pushing on you.

MilanD

I can't believe your downstairs neighbor can't hear it. Well, let's hope those ells and pipes below the floor will fail soon, start dripping through the ceiling into the apartment below and then they'll have to open up the ceiling and replace and repitch everything. Man...

In this co-op, do you own your unit, or you rent it? Sorry, I'm not familiar with co-op setup. Why can't you get your own person to fix this if you own your unit?

In Ohio, if the landlord ignores requests for fixing issues that are mechanical and considered his responsibility and not something that's caused by the tenant (so not tenant breaking a window or punching a hole in the wall during a party and then asking the landlord to fix it), tenant can hire his own expert, at arm's length (not a buddy), and legit deduct it from the rent, with a letter to the landlord and a copy of paid invoice for the said work performed.

So in a nut shell, the management sent 'someone else' who replaced an otherwise functioning convector with a new one that now also stinks, called it 'good', and MAYBE the contractor raised the intake as it bangs somewhat less now... So, have them raise it some more, or better yet , do it yourself. It won't take much material to prep it: hammer, chisel (maybe, what's below the rad), oscillating cutter with a good blade, short piece of 2x4 and a breaker bar, or 6 ft long 2x4 to push up with. Pic attached.

Can you just move back to your old unit?

MilanD

BTW, why don't you upload to YouTube a video of the radiator when it's banging, and share it here? Can then start building a case for the management too.

coophammer

Thanks guys - and appreciate the illustration - but I am not skilled enough to do my own plumbing, I admittedly joined this forum in the first place for the guidance from you guys, the talented folk, and can do smaller tasks myself - but cutting into the cement and lifting up the pipes is something i unfortunately cannot do.

I have audio of the banging, I can find it and share it here. I wish I could record SMELLS.

MilanD

You can do a pic of your face reacting to the smell!

Chris posted this a few weeks back

coophammer

Hello all, I wanted to post an update. This steam/water hammer has become more of a nuisance to me, as I'm a new father, and the clanging is waking up my baby during precious sleeping hours.

Anyhow here's where we are at, with an illustration included for good measure.

- Bedroom 1 has a new heating element/radiator, with a good pitch. It has new everything. Air valve, main valve. Bedroom 1 main valve is completely closed, as my wife and I don't like a hot room to sleep in.

- Bedroom 2 same as above, good pitch on the heating element, new valves, but main valve is fully open, to warm up the baby's room.

I hear the loud, clanging water/steam hammer in both rooms. Perhaps even louder in bedroom 1 (closed valve). The noise seems to be right in front of the heating element.

I can hear exactly when the noise will begin. I hear the sound of air/steam coming up, gaining momentum, and I imagine what then happens is the main steam source surges is, hits condensate very quickly, and it hits a joint that connects both rooms with heat, because the clanging is heard loudly in both rooms... so the condensate must be hitting a horizontal joint and going both directions.

I am pleading with my building manager to hire a STEAM SPECIALIST. They have a bureaucratic way of hiring plumbers that they've worked with before, but these guys aren't familiar enough with steam issues.

My super has told me things in the past about how the noise is just coming from my unit, I'm the only one complaining, it's an old building, if I have to break the floors my downstairs neighbors would never agree to it, etc.

But I'm at my wits end....

The most promising suggestion, I think, is to try and lift the heating elements 1/2"-3/4" with a plumbers help. But of course I'm not sure that the horizontal joint is the problem.

Would a steam specialist be able to diagnose where the problem area is? How would he do it?

And if I have to break the floor to fix a pipe, or add some kind of pipe attachment to lessen the pressure... what would that involve? How big of a job would that be? And would I have to break my downstairs neighbor's ceiling to be able to do it?

Previously I wrote that my super told me a vertical pipe brings the steam to each floor, below the heating element. But this actually doesn't make sense to me, because there is an exposed heating pipe in the bathroom. So I would think there are feeder pipes off this main pipe that run along the floor... and that one of these feeder pipes are sloped poorly.

Also - what if the co-op board doesn't want to pay for this? Does anyone know if a faulty steam heating pipe is the responsibility of the shareholding tenant or not? Also, what about noise issues, aren't we supposed to be able to live in peace without this nuisance every night?

Thanks for reading.

Here is the illustration to show where the exposed heating pipe is, and why I think my super was incorrect to tell me that there is a vertical pipe under the heating element.



Also - there is a darker, raised area on my floorboards near the heating element. I pressed my foot down on this area and I could hear pipe. So I'm able to push the pipe up and down directly in front of the heating element. So perhaps a loose pipe is also adding to this noise... and perhaps if the wood is already raised, and weakened, as it is, it won't be a huge thing to open it up and fix the pipe (if that's even a possibility to fix this issue)... I don't know where the issue lies.

Here's a blurry shot of that area in front of the heater in bedroom 2- you can see the darker line, where I was pressing my foot.

neilc

Are you able to raise / pull up that pipe as it enters the cabinet thru the floor? (gently)
Ideally you would raise that as much as possible, gently,
then re pitch the element if required.
Where you say you hear pipe as you step on that line in your floor, do you see any movement at the pipe thru the floor in the cabinet?
I'm having a little trouble envisioning pipe tight up against your floor, and a sag there, but who knows?
Is the floor level ? check with a level, or a little water in a cookie pan,
does a ball roll down hill?

nicholas bonham-carter

The steam specialist might well do first what you are proposing to do: lifting the whole radiator up an inch or two.
What needs to be broken is not in your neighbors ceiling, but in the mindset of the Co-op management. One might possibly think that the plumbers they hire provide kickbacks to the managers for the work they do.
I am sure the changes they made to your radiators had no effect on curing the problem.
The steam heating system is an element common to the whole building, and the symptoms you have are resulting from some sort of deferred maintenance of that system. I would also consult a lawyer who has experience with dealing with these issues of Co-op law. There will be many opportunities for that lawyer, if he advertises here, to help many others in your situation.—NBC

https://www.nytimes.com/2018/01/26/realestate/when-a-co-op-board-misbehaves.html

Jamie Hall

Something to watch out for; that "closed" valve. Is that the inlet valve to that radiator? One pipe steam inlet valves have been known to cause some pretty bad water hammer when they are closed -- since they don't close completely, particularly older ones.

Can you close the vent on that radiator instead? That's a better way to shut off a one pipe steam radiator...

coophammer

neilc said:

Are you able to raise / pull up that pipe as it enters the cabinet thru the floor? (gently)
Ideally you would raise that as much as possible, gently,
then re pitch the element if required.
Where you say you hear pipe as you step on that line in your floor, do you see any movement at the pipe thru the floor in the cabinet?
I'm having a little trouble envisioning pipe tight up against your floor, and a sag there, but who knows?
Is the floor level ? check with a level, or a little water in a cookie pan,
does a ball roll down hill?

The floor is pretty level, slightly downhill from the heater, if anything, which should benefit the noise, right..
I think I see some minor movement. I wouldn't be comfortable raising the element without a plumber of some sort.

nicholas bonham-carter said:

The steam specialist might well do first what you are proposing to do: lifting the whole radiator up an inch or two.
What needs to be broken is not in your neighbors ceiling, but in the mindset of the Co-op management. One might possibly think that the plumbers they hire provide kickbacks to the managers for the work they do.
I am sure the changes they made to your radiators had no effect on curing the problem.
The steam heating system is an element common to the whole building, and the symptoms you have are resulting from some sort of deferred maintenance of that system. I would also consult a lawyer who has experience with dealing with these issues of Co-op law. There will be many opportunities for that lawyer, if he advertises here, to help many others in your situation.—NBC

https://www.nytimes.com/2018/01/26/realestate/when-a-co-op-board-misbehaves.html

Thanks for the link and the advice. I hope I don't have to go the legal route, as we need other things from management from time to time, and I don't want a combative relationship.

Jamie Hall said:

Something to watch out for; that "closed" valve. Is that the inlet valve to that radiator? One pipe steam inlet valves have been known to cause some pretty bad water hammer when they are closed -- since they don't close completely, particularly older ones.

Can you close the vent on that radiator instead? That's a better way to shut off a one pipe steam radiator...

I can close the vent - but I don't think it will make any difference. I have had both elements open in the past, and it made no difference. The problem has to be condensate sitting somewhere in the pipes under the floors, or somewhere above my downstairs neighbors system.

Fred

I'm assuming the steam supply pipes come into the end of the convector and not into the middle, like you drawing shows. Is that correct? If it comes into the center of the convector, then the convector would have to be pitched back towards that pipe and not to one end.
Also, have you asked the neighbor below you if they have any hammer? It may be that the source of the hammer is coming from elsewhere and radiating up the supply pipe.

coophammer

Fred said:

I'm assuming the steam supply pipes come into the end of the convector and not into the middle, like you drawing shows. Is that correct? If it comes into the center of the convector, then the convector would have to be pitched back towards that pipe and not to one end.
Also, have you asked the neighbor below you if they have any hammer? It may be that the source of the hammer is coming from elsewhere and radiating up the supply pipe.

Fred sorry for my crude drawing - it connects at the end, as you can see here:


My neighbors downstairs claim that they don't hear anything. They complain a LOT so either my super is lying when he says that they aren't complaining, or they aren't hearing anything. It's possible that there is enough space in the space between our apartments that it doesn't bother them?... I don't know

Fred

Is there any way to stick a probe type inspection camera in any opening in the floor? It would be interesting to see how/where the horizontals to each bedroom connects and might also allow you to see if there is pitch in those horizontals.

coophammer

Fred said:

Is there any way to stick a probe type inspection camera in any opening in the floor? It would be interesting to see how/where the horizontals to each bedroom connects and might also allow you to see if there is pitch in those horizontals.

I agree I wish I could do something like that, but I have no idea where a probe camera would fit... the fact that I was able to push my foot down where the floor is beginning to split told me at least that there was a warm pipe underneath. I can try to do that along the rest of the floor to try and get an idea.

nicholas bonham-carter

I wonder if a steam valve operating in reverse could cause any problems, as it looks like the spud is screwed into the supply pipe, and a regular nipple into the rad.
If you could put a low pressure gauge onto the air vent tapping, I wonder if the pressure would be seen to be too high

.

Fred

You can drill a 3/4" hole in the floor inside the convector cabinet to drop a flexible probe type inspection camera in and look around. When you're done. plug the hole with a cork from a wine bottle, drink the wine and I bet you won't hear the banging or the baby. At least for a few hours.

JUGHNE

If the supply line coming up thru the floor can tip/swing to the right, then raising the convector that much on the left end could tip the right end with the elbow down to where it is holding water.

Have we seen this picture on another posting?

Could you adjust the fin tube so there is less slope on it and maybe that elbow would be draining. That much slope will certainly drain the fin tube but could be allowing water in the elbow to pool.

coophammer

JUGHNE said:

If the supply line coming up thru the floor can tip/swing to the right, then raising the convector that much on the left end could tip the right end with the elbow down to where it is holding water.

Have we seen this picture on another posting?

Could you adjust the fin tube so there is less slope on it and maybe that elbow would be draining. That much slope will certainly drain the fin tube but could be allowing water in the elbow to pool.

Jug, sorry I'm not familiar with some of the terms you are using. You are saying if we can lift up the convector in bedroom 2, that it could maybe make some slope under bedroom 1?

Also not sure what is a fin tube?

coophammer

nicholas bonham-carter said:

I wonder if a steam valve operating in reverse could cause any problems, as it looks like the spud is screwed into the supply pipe, and a regular nipple into the rad.
If you could put a low pressure gauge onto the air vent tapping, I wonder if the pressure would be seen to be too high

I know that before when I asked the plumber and super - I was told the building ran on 5 lb of pressure. The people in this forum told me that was way too high. But I was told off - with some explanation about low, med, high pressure systems... it was a while ago so I don't remember completely.

But these people are very stubborn. And I have a feeling that a high pressure system that they are using is to avoid fixing other issues such as boiler or buildup issues. Instead they neglect and bump up the pressure. But I don't know for sure.