Water Hammer in Steam Heat System Throughout House (plus spitting radiator)

rarach

My husband and I have a loud water hammer in our steam heat system. We have someone coming out to look at it next week, but know that steam is a "lost art," so we would like to try to diagnose before he comes out, so there is some direction to the $ visit. Here are all the facts I can think of.
Info on system:

• One pipe steam system, 7 radiators, 3 on first floor, 4 on second floor
  
• Boiler type: EG PEG Weil-McLain (MAWP Steam 15 PSI, MAWP Water 50 PSI, Max Eater Emp 250 F, Min Relief Valve Capacity 125 LB/HR) -Note that I have no idea what any of this means, but it's on a sticker on the boiler.
  
• Radiators appear properly pitched after testing with level.
  
• Unsure about whether pipes are properly pitched. Some of the pipes seem angled, but some are parallel with the ground and not pitched.
  
• House is 90 years old. We have been in it 3 months. There was a gap between us and the prior owners (they rented it) and prior owners claimed to have not had this issue. They mentioned something about replacing vents (I plan on doing that and got excellent help in another post), but I really don't think it's our issue.

Sound in each radiator:

• Master Bed 1: Hammering sound hits like a really really loud bang followed by some sputtering fireworks-like noises.
  
• Master Bed 2: Hammers in a series of loud bangs.
  
• Guest Bed: Light hammering, with loud hissing.
  
• Office: This one was initially the only one that hammered. It is a second-floor radiator with no first floor counterpart (but does have a long exposed pipe running up the first floor). Banging occurs in the pipe and in the radiator. It was initially spurting out a lot of dirty brown water. We replaced a verivent with a slower venting valve (crappy plumbers edge from HD -should replace soon based on other advice from this site). It quit spurting water and hammering died down for a bit, but now continues to do so occasionally, but not as much. The radiator blows out cool air when it's starting up, and you can hear it 'whistling' in and out for quite a while, which is finished off by a little spurt of water, and then heat. This might be the panting sound described by Dan Holohan in situations where there has been flooding. A little more about the downstairs pipe: The pipe makes such a loud noise from water hammer it seems like the whole thing is going to rip out. When the pipe makes this noise, you can feel and see it moving and adjusting. If you hold the downstairs pipe, it shakes a little, even when cold.
  
• We believe all hammering is mid cycle.

Other evidence:

• I had the boiler serviced and was told the water inside was very dirty. It was flushed out twice then refilled. Hammering got worse after this (although I can't say this was the cause). Perhaps it was filled too high? Sight glass is now murky. Unfortunately, I didn't know enough about steam heat to look at the glass immediately after servicing, but it was probably clear following the service, but I can't be sure. Note that this happened AFTER the banging situation described above about the office radiator. That situation was not caused by the servicing. However, things have gotten louder in the other radiators, so perhaps it did exacerbate something.
  
• The water that spurted out of the office radiator was brown and full of sediment.
  
• Our tankless hot water heater broke a few weeks ago. It was replaced the day after the boiler was serviced. The issue was water leaking in the heat exchanger and likely due to faulty plumbing casing condensation water to rush back into the system instead of leave through outdoor pipes. I have no idea how this could impact our steam system, but might as well mention it.
  

I've attached various pictures of the boiler for reference. And yes, I do need to insulate. That is on the to-do list! However, the sound isn't at the beginning of the heat cycle, so I don't think that is our main issue.

If anyone has any clue what is going on, that would be so helpful! Also, if anyone recommends a steam expert in Westchester NY, please let me know. Also, maybe I can convince someone from NYC to come up if next week's guy doesn't work out.

Thank you and either way, I'll try to post the ultimate solution so this can help others.

JStar

Right off the bat, that copper doesn't belong on the supply. That's likely why the water is so dirty. It's the boiler rotting away from dissimilar metals reacting.

The header looks like it has a reducing elbow, and possibly back-pitched after it converts to copper. That'll hold water in the header and cause noise and other issues.

The hartford loop connection nipple is too long. The elbow from the return should be as close to the equalizer as possible. This would cause hammering.

Outside of these near boiler issues, you may have condensate sitting in an improperly pitched pipe, but the boiler piping should be addressed at some point.

Jamie Hall

As @JStar said (he's one of the best, and I'm glad he's back in battery!) your near boiler piping isn't doing you any favours at all. However... in a 90 year old house, with probably original pipes, I'd be inclined to check every single horizontal or near horizontal run of pipe for pitch. One pipe systems are particularly subject to troubles with pipes which have lost their pitch or sagged -- and 90 year old houses sag. Don't just check end to end -- make sure the pipes are straight in between ends!

On water level -- I honestly can't make out where it is in the sight glass, but my eyes are none too good so that's probably me. In any event it should be about half way to two thirds of the way up the glass.

Pressuretrol -- again, I can't really make it out, but it looks as thought the cutout (scale on the front) may be set high -- try setting it around 0.75 to 1.

ethicalpaul

I mean it’s not perfect but we’ve seen WAY worse lately!

Neild5

Hammer is a sign that there is water in the pipes. To make sure there is no sagging pipes, tie a string to both ends of the pipe and have it real taut. Sags will be easier to find this way.
Your pictures are very helpful to assist you in diagnosing your symptoms.

acwagner

I see from your photos that you have two mains from the header Are your problematic radiators all on one main or split between both?

When the boiler is running watch the water level and see what it does. Let us know how much it moves within the site glass.

I see only one main vent. Does the other branch have one?

It would be useful if you could figure out your radiator EDR so we can compare to the boiler rating.

I also saw your other post regarding radiator vents--I would wait before installing new vents until you get the hammer under control. Might end up damaging your new vents and you'll have to buy replacements.

Fred

It looks like the water level in the sight glass may be all the way to the top. If so, drain water out until it's about 2/3 (max) up the glass. The other question is: When they serviced the boiler, did they take the Pressuretrol off and clean out the pigtail (looped pipe the Pressuretrol is mounted on)? If they did not, that pigtail could be clogged and the Pressuretrol can't see or manage the system pressure. If the pressure gets too high, it could prevent condensate from returning to the boiler.
Clean the pigtail and make sure the Pressuretrol is set at .5 to .75PSI (on the scale on front of the unit) and set the white wheel inside the Pressuretrol to "1" facing out.

BobC

Mid cycle hammer can be cause by a combination of overly fast radiator venting and radiator runouts that are close the maximum edr ratings.

What kind of radiator vents are being used and what size are they? In general you want to vent the steam mains fast and the radiators slowly. Heat timer vents can cause problems because they can vent very fast, USAV vents from Home depot are crap and should be avoided.

Make sure all piping between the boiler and each radiator has some slope so water can find it's way back to the boiler and check the piping for sags as someone above mentioned.

Bob

rarach

acwagner said:

I see from your photos that you have two mains from the header Are your problematic radiators all on one main or split between both?

When the boiler is running watch the water level and see what it does. Let us know how much it moves within the site glass.

I see only one main vent. Does the other branch have one?

It would be useful if you could figure out your radiator EDR so we can compare to the boiler rating.

I also saw your other post regarding radiator vents--I would wait before installing new vents until you get the hammer under control. Might end up damaging your new vents and you'll have to buy replacements.

I will look into the EDR when I get home. Unfortunately, all this is happening during the workweek, so it was hard to even get photos and make the post. Does EDR have to do with "overfiring" a boiler?

rarach

BobC said:

Mid cycle hammer can be cause by a combination of overly fast radiator venting and radiator runouts that are close the maximum edr ratings.

What kind of radiator vents are being used and what size are they? In general you want to vent the steam mains fast and the radiators slowly. Heat timer vents can cause problems because they can vent very fast, USAV vents from Home depot are crap and should be avoided.

Make sure all piping between the boiler and each radiator has some slope so water can find it's way back to the boiler and check the piping for sags as someone above mentioned.

Bob

Thank you! I know the vents are too fast (they are verivents). So I have another post on this forum where I ask specifically about vents. Prior to this, I think there was a little hammer because of the vents. But now the hammer is really bad. I am starting to think the boiler water level is to blame. I will be placing new maid-o-mist vents on after I figure out how to get this water out of the system (as someone above mentioned).

rarach

Fred said:

It looks like the water level in the sight glass may be all the way to the top. If so, drain water out until it's about 2/3 (max) up the glass. The other question is: When they serviced the boiler, did they take the Pressuretrol off and clean out the pigtail (looped pipe the Pressuretrol is mounted on)? If they did not, that pigtail could be clogged and the Pressuretrol can't see or manage the system pressure. If the pressure gets too high, it could prevent condensate from returning to the boiler.
Clean the pigtail and make sure the Pressuretrol is set at .5 to .75PSI (on the scale on front of the unit) and set the white wheel inside the Pressuretrol to "1" facing out.

Based on this, I'm going to call the plumber who did the servicing and see if they can come and reduce the water level for free. I believe their tech refilled it too high. The water level is right at the top. When it runs, it sloshes around a little but doesn't seem to jump too high, but it's hard to tell because it's already too high. I'll ask them about the pigtail too. Hopefully, they don't charge extra for that. My area is just so expensive...

Do you happen to know if the tech could have flooded the system doing this? I would hate to think an already expensive servicing just cost me more money.

rarach

JStar said:

Right off the bat, that copper doesn't belong on the supply. That's likely why the water is so dirty. It's the boiler rotting away from dissimilar metals reacting.



The header looks like it has a reducing elbow, and possibly back-pitched after it converts to copper. That'll hold water in the header and cause noise and other issues.



The hartford loop connection nipple is too long. The elbow from the return should be as close to the equalizer as possible. This would cause hammering.



Outside of these near boiler issues, you may have condensate sitting in an improperly pitched pipe, but the boiler piping should be addressed at some point.

Thank you so much for your response. It is good to know why the water might be so dirty. As for the condensate in the pipe issue, everyone keeps talking about pipes being pitched, which they do seem to be, but does it matter that there is a pipe running along the ground? It would eventually need to move up to get back into the boiler, right? I can't see how it does this, because there are walls around this part. I got a few pictures of it running low near the floor. This must have been original, so I'm assuming this is fine and I just don't know what I'm talking about, but it seems to go against everything I'm learning on this site.

Jamie Hall

High water level is certainly part of your problem here. Probably not all of it -- but it doesn't help. There should be a drain on the boiler somewhere -- it's easy enough to correct: open the drain and let the water out until it's right. But a note -- if the water level in the sight glass doesn't change as you let water out, it may be that the connections from the sight glass into the boiler are blocked, or partly blocked, which will need to be cleaned out.

Pipes running around the place below the water line of the boiler are not a problem, so long as they stay below the water boiler line. They are referred to as wet returns and, while they can and do clog up (and sometimes leak!) their actual routing is pretty flexible. The water at both ends will stand at the same level; any water which goes in at one end will push water out the other. These pipes don't have to be pitched, though they often are.

Pipes which are laid horizontally near the water line can be very problematic. They should be either well above -- or clearly below. This can be a problem when a boiler has been replaced with a smaller one, and the water line lowered.

Pipes which are well above the water line are either dry returns -- bringing condensate and often air back to the boiler or on to a vent or a "drip" (a vertical pipe going down to a wet return) or are steam mains or runouts. Both of these need to be pitched so that the water -- condensate -- which they carry can clearly flow either back to the boiler or to a drip. In older houses it's not at all uncommon for the proper pitch to be lost as the house sags, or for low places to develop. This can cause an inordinate amount of trouble. Particularly villainous are short horizontal sections in radiator runouts connecting risers to radiators -- the riser doesn't settle, but the radiator does and a low spot develops and water collects and hammers or cuts off the heat. These can be hard to find -- and if the pipe is close to the floor above it, next to impossible to fix without pretty major carpentry and plumbing. (Really old houses, with all the piping exposed, are a piece of cake!).

EDR is a measure of the size of the radiators, which in turn controls how much heat they can radiate, which in turn controls how much heat they can absorb from the boiler. It's related to boiler size in that if the boiler is too big, the boiler will have to shut off from time to time so that the radiators can catch up. Steam boiler nameplates have -- or should have -- their nominal capacity shown; it will say square feet of steam or something like that. However, boilers can sometimes be down-fired so it isn't always a perfect guide.

BobC

@rarach For my money it's hard to beat the maid O Mist that comes with 5 orifices and the Amazon $15 price is a no brainer. I've had them on my system for 3 years and had no problems with them.

Start with the smallest opening on the fisrst floor rads and the next size up on the 2nd floor. let the system run for a few cycles and increase the vent size on anything that is really slow to heat. make sure the main vents are big enough to get steam to all the radiator feed pipes at about the same time.

Bob

STEAM DOCTOR

I am not a big fan of the maid o mist vents. I have replaced many of these vents that were leaking around the seam. The Gorton's are more expensive but they are worth the money in my opinion

JUGHNE

Everything above,
I see at least 2 points you can drain water out of the boiler.
One has a white handle on a ball valve, the other is a small boiler drain with garden hose connection. As mentioned the removal of water should be reflected in the sight glass level dropping to insure the inlet to the sight glass from the boiler is not plugged.

With the boiler off and cool, if you unscrew the pressure gauge and get a 2" long 1/4" nipple to insert, get a foot of rubber hose that fits tightly over the nipple. You should be able to easily blow into it, there may be an initial resistance as you push the trap water in the pig tail back into the boiler. If that is clear then add water thru the hose to refill the trap, you should hear water dribble back into the boiler. Remove your test equipment and reinstall the gauge. Do you see the gauge move when the boiler has been firing?? what pressure is shown?

Are the copper riser pipes coming out of the top of the boiler the high point of the steam piping?
From that point follow them around the basement, they should slope down hill from the high point at the boiler. That same slope should continue on the return piping. All the run out pipes to the radiators should be such that any water in them will drain back to the main. Think of all the piping as a drain system that should drain down dry when done.....except the wet return which is always full of water.

When the boiler shuts down all the water in the system should drain back thru the return piping into the boiler. Or if you have wet returns (pipes below the sight glass water level) that part of the water system should drain down into the wet return and then into the boiler.

You could have slow return of water in the wet returns that are partially plugged. The auto water fill adds water during the boiler cycle because of slow return, then after shut down the tardy water eventually comes back and over fill the boiler.

We all would recommend the book "We Got Steam Heat!" from the book store above. Written for the layperson/home owner.
You would learn a lot and avoid a few service calls.

rarach

@JUGHNE The book, We Got Steam Heat is on Kindle, so I'll download asap. I'm having the company who did the servicing send someone out to fix it (I'll confirm it's free). Hopefully, after I read the book, I'll understand more of what you and everyone on here has said. Thanks!

rarach

@Jamie Hall thank you so much for your explanation! I clearly have no clue about anything and will be reading "We Got Steam Heat" as soon as I get home from work. I'll also look into the boiler EDR more.

ethicalpaul

STEAM DOCTOR said:

I am not a big fan of the maid o mist vents. I have replaced many of these vents that were leaking around the seam. The Gorton's are more expensive but they are worth the money in my opinion

Fair enough, everyone has their favorite, but you're seeing the problem cases especially focused. Who calls you to say "I don't need anything, but I just wanted to tell you my MoM vents are still working!"

Fred

@rarach , that valve low, on the boiler, under the sight glass, with the white handle is the valve to open to drain water out of the boiler. I am sure the ports into the sight glass are not plugged or the water level would not have gotten that high and the water would not have changed from clear to a tea color. Make sure the boiler is cool enough that you don't scald yourself when draining water and open the valve slowly, with a bucket under it to catch the water. The water level being that high is a huge factor for water hammer as the water is being blown up into the system and there is no room for steam, in the boiler itself. Drain the water level down and let us know if that resolves the water hammer.

rarach

@Fred Thank you for your advice about how to drain it. I will have the company that filled it too high do this (and monitor it) and make sure the system is off and cooled before they do. The thing is, what about the water already in the system? Will that work its way out? Or do I need to somehow get it out of there?

STEAM DOCTOR

> @ethicalpaul said:
> (Quote)
> Fair enough, everyone has their favorite, but you seeing the problem cases especially focused. Who calls you to say "I don't need anything, but I just wanted to tell you my MoM vents are still working!"

I know that I see the problem cases. Many more of the those cases involve MOM's then Gorton's. By a significant amount. I have been in endless homes that have mix of MOM's and Gortons. The failure rate is not close. The MOM's are crimped (the backplate). The Gorton's are soldered. MOM's also also have a plastic float. My gut feeling is that the plastic floats can't take the high temps, causing them to end up disfigured and out of shape. That would cause them to not rise properly and not seal properly. Would explain why lots of the MOM's leak steam from the the top hole.

Hap_Hazzard

They're crimped, but they have a neoprene seal on the backplate. I can't see that leaking. I'd expect a solder joint to be more failure-prone.

JUGHNE

The company that filled your boiler may not have been the cause of the overfilling. That could be late returning water that was hung up somewhere and eventually found it's way home.

This just happened to me on a service call.....filled cold boiler to the right level.....2 days later on the next firing it flooded.....no auto fill on it, just water was hung up somewhere and the next shot of steam sent it back.

Rather than call the company, IIWM, I would drain the water back down myself and then see what happens for the next heating cycles.

STEAM DOCTOR

> @Hap_Hazzard said:
> They're crimped, but they have a neoprene seal on the backplate. I can't see that leaking. I'd expect a solder joint to be more failure-prone.

I see many of them leaking from the crimp area. Cant remember seeing any Gortons leaking from the solder area.

ethicalpaul

STEAM DOCTOR said:

I know that I see the problem cases. Many more of the those cases involve MOM's then Gorton's. By a significant amount. I have been in endless homes that have mix of MOM's and Gortons. The failure rate is not close.

I'll never argue with your experience, and thank you for sharing it here! I'll let you know if one of mine goes out.

clammy

I would suggest you have some one attempt to flush out your wet return and aside from all your issues I would suggest to also look into getting your steam mains and piping insulated . As other may have stated the near boiler piping looks like it could use some t l c . Personally if it is flooding I would lower the water level to the correct level and shut off the water feed line to boiler and see if the boiler shuts off due to low water and how long it takes for condensate to return and bring your water line back to where it started . If the condensate does not come back or is very very slow and the returns can’t be flushed then replace and add isolation valves and drain valves for future flushing . In some case slow clogged return trigger the automatic feed resulting in a flooded boiler and a ton of noise and if it floods high enough damage to main vent ,and when it does happen the boiler will need to be flushed well and possibly the returns . In most cases a flooded system results in all types of debrie returning to roost in the boiler causing surging and will sometimes require more then one skimming . Find some one well verses in steam heating and make sure they know what there doing not just guessing. Use the find a pro listing on this site it s your best bet on getting it operating correctly Peace and good luck clammy

Fred

@rarach , You don't need to worry about water out in the system as long as the overfilled water level is at the boiler. It looks like the water is up to the top of the sight glass so it hasn't filled the header or mains. Just be sure to lower the boiler water level and watch the serviceman when he lowers the water level so you can do it yourself if you need to. If after he lowers the water level, you notice the boiler overfills again, either the Auto refill unit needs to be adjusted or water is leaking past the fill valve in the auto fill unit and it may need to be replaced but take it a step at a time and get the water level lowered.

rarach

> @JUGHNE said:
> The company that filled your boiler may not have been the cause of the overfilling. That could be late returning water that was hung up somewhere and eventually found it's way home.
>
> This just happened to me on a service call.....filled cold boiler to the right level.....2 days later on the next firing it flooded.....no auto fill on it, just water was hung up somewhere and the next shot of steam sent it back.
>
> Rather than call the company, IIWM, I would drain the water back down myself and then see what happens for the next heating cycles.

This is disheartening, because I was hoping for an easy fix. Silly me. I’m confused as to how far lower the water. People keep saying 2/3, but the machine says no more than 1” (see photo).

I also noticed my home’s water pressure is too high (over 100 psi). Could this affect the boiler somehow?

ethicalpaul

I think you're misunderstanding the label. It is saying that you shouldn't operate with the water lower than 1/4" above the bottom of the glass, and...

...that you MUST NOT EVER operate with the water lower than 1" below the bottom of the glass.

Now how you can tell when the water is 1" below the bottom of the glass, I have no idea

Anything between 1/2 and 2/3 of the glass filled is totally fine (depending on quality of steam of course...I'm just talking about safety).

rarach

@ethicalpaul Ohhh. I was confused for the exact reason you point out. My brain couldn’t fathom measuring something I couldn’t see, so I found a point where I could! Thank you!

acwagner

Your boiler manual will have the recommended water level in it. Typically it's measured from the floor. I believe for your model boiler it says 23 13/16" from the floor, but you should double check.

You can measure the normal water height and put a piece of tape or use a marker to mark the height on the rods next to sight glass.

First, drop the water level and and observe it for a few days to see if it is rising or not.

ethicalpaul

rarach said:

@ethicalpaul Ohhh. I was confused for the exact reason you point out. My brain couldn’t fathom measuring something I couldn’t see, so I found a point where I could! Thank you!

It's really poorly written and definitely would be a source of confusion. I'm sure a lawyer made them put it on there and told them the language to use.

rarach

Update: Just had water in the boiler lowered to the proper level. The auto-refill was reset so that it refills a little less quickly. I can't remember exactly what the settings were vs what they are now, but hopefully, this helps things. If the issue persists, we may need our wet return cleared out as suggested above. I also learned that our hartford loop is much higher than the boiler manual calls for (basically it's at water level).

JUGHNE

If your pressure gauge is correct showing over 100 PSI you might consider a pressure regulator for your entire house. Pressure like that can cause some serious water hammer in your washer, dishwasher and icemaker. (this is hammer in your hot and cold water lines in your house.....not your steam system)

Also the auto water feeder to the boiler is adjusted by the time it is open. The pressure you have there will pass more water than usual. (also induce water hammer in your house plumbing as mentioned above). IMO