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Water Rushing Noise - Woke me up this morning - splendid!

Hello All!

First, this website is an amazing source of information and I think I have felt out what, I think, might be the issue - but want to run it by everyone here as well.

My wife and I purchased a colonial from the 1890's last year and are becoming acquainted with the sounds and personality of our heating system (single pipe steam).

Last night I was awoken to what sounded like surging water through the pipes that supply heat to that radiator. I immediately jumped up expecting my floor to be a wave pool, but no, no water anywhere, and the radiator was functioning (hot) but just a very loud surging sound. Now we are quite used to the sound that steam heat generates - but this seemed out of character. This radiator is on the longest run in the house and in an extension that was added in 2011 or so. I am sure this was not part of the original systems design. The radiator is pitched slightly towards the supply thanks to the help of some loose change under the feet. This is the troublesome radiator in the house: the only one with any water hammer (very lightly when steam starts and turns off).

Full disclosure I did replace the air vent on this radiator around 2 months ago as it was not fully heating and the room was significantly cooler than the remainder of the house. The vent was rusty and I cleaned the area surrounding it before in stalling a new vent. Don't scoff, but we used a home depot - cheap vent when we did it as we were testing a theory - and should likely replace that vent at some point. This has helped, but the room is still not as warm as the rest of the house, but I digress.

I am wondering if the new vent is venting too fast, and it is causing an issue with fresh steam condensing too quickly and making noise. I know, I know, vent the mains fast and the radiators slow. The vent is adjustable, so I am thinking of turning it down a tad and seeing if we get this issue still. Eventually I would like some advice on a replacement vent choice and size - but I will need to provide much more information for those recommendations I am sure.

Below is a video that I took right before I got up - so it is pitch black - but if you turn the sound up you will hear the noise. Bear in mind that is about 5 feet away from the radiator in question, to clue you into how loud it was. Don't mind my wife telling me to go down and turn the heat off at the end :)!

Thank you in advance for any insight!




  • jkevinholmesjkevinholmes Member Posts: 20
    Some additional heating system pictures - just so you can see. The two mains are pictured as is the near boiler piping and some other settings/info.

  • JUGHNEJUGHNE Member Posts: 4,144
    Your main vents look too small....upgrading them would be the low hanging fruit for improvement.

    Looking at your boiler piping it is surprising you don't have more issues.
    You can find the install book for that model number to see piping diagrams.
  • jkevinholmesjkevinholmes Member Posts: 20

    Thank you for your response.

    What other issues might I be experiencing, maybe I just don't notice?

    Also, what size, brand, vents would you recommend - or what details would you need to make that recommendation!

  • JUGHNEJUGHNE Member Posts: 4,144
    For main air vents I would recommend Gorton #2's.
    They have a float that would close if you had any water try to spit out.

    What pressures do you see on the gauge when it operates?

    With your piping you might expect to get "wet steam" in the mains which could contribute to your water sounds.
    Don't panic.....there are a lot worse jobs that work after a fashion. Some minor improvements can help a lot.

    It would best to get the book "We Got Steam Heat!" by Dan Holohan. A great primer for homeowners, easy and interesting to read. Look above in the "store" or online.
    Then next would be the "Lost Art of Steam Heating", same store, same man.

    Even reading here you come across people with the same issues and they post pictures as you did.
    Pictures will usually bring up a lot of advice and suggestions.
  • ImYoungxDImYoungxD Member Posts: 33
    edited February 28
    Your water level is like 95% full
    It should be 1/2 or 2/3 in that glass. Try 1/2

    Do you have an automatic water feeder? It may be dirty and needs to be cleaned.
  • JUGHNEJUGHNE Member Posts: 4,144
    Good catch, I was looking at everything else.
    Drain water from the green handle valve of the boiler.

    I don't see an automatic feeder, just a manual feed piped in too high on the equalizer line. If you add water there while steaming it could give water hammering in the steam equalizer.

    Too much water in the boiler can throw water up into the steam system. That could have been what you heard.
    That 1/2-2/3 level would be when not operating and after all water returns to boiler. Water may take long to return for a variety of reasons. the book...... ;)
  • FredFred Member Posts: 6,312
    edited February 28
    A couple issues I see, other than the near boiler piping.
    1. The pressuretrol looks like it is set at about 4 PSI Cut-In (Scale on front) and the Differential (white wheel inside the unit) is probably set at at least "1". That makes for a Cut-out pressure of 5 PSI. That is way too high and probably doesn't let the condensate return back to the boiler. Set the Cut-in to .5 PSI and make sure the Differential is set to "1".
    2. The other added possibility is the horizontal pipe that feeds that radiator may have lost its pitch, back towards the Main. Try to raise the entire radiator about a half ot three quarters of an inch and then repitch the radiator back towards the supply pipe. Raising the entire radiator will create some pitch in the pipe that feeds the radiator.
    As has been said, get some decent vents on those mains, Gorton #2, I prefer the Barnes and Jones Big Mouth, available from Amazon.
  • jkevinholmesjkevinholmes Member Posts: 20

    Thank you a ton for your responses, this is exactly what I was hoping for - some manageable suggestions to try before bringing in the big guns if need be!

    So I did buy the "We Got Steam Heat" book - but purchased it right before summer, so I "ran out of steam" ... I know it was terrible!

    As for the water level - those are pictures from when I first moved in - this has since been corrected and it sits at the appropriate range. Fun story - 2 months into being a first time homeowner, heat stops working and I cant figure out why. There is plenty of water in the sight glass (as you can see in that picture) - but the low water cut off is ON. Thanks to this site, I was able to diagnose that the valves to the sight were closed, and the water was indeed below the appropriate levels. Added water - boom - heat again! Huge sigh of relief for me and my wife!

    So this year I have had to add water twice - not much either time - but enough to get it back to the appropriate level. When I add water - there is some sediment that fills the sight glass - I am wondering if that has anything to do with the fact that you say the supply line is to high up?

    After shutting the heat around 4AM this morning - I woke up around 6:30AM and checked the water levels, figuring that was enough time for the water condensation to return. The levels were appropriate - so I think we can rule that out!

    Periodically throughout the season I have drained some water from the bottom (valve pictured below, which I truly hope is the right valve to use). My realtor (who also has steam) said to do so until the water runs clear and then add fresh water. Only when the system has been off for a while and the water has had time to return. Is this a blowdown? Should I be doing so? You can see my clear bucket that gets quite gross!

    So speaking of wet steam - once and a while the radiator in the kitchen will have a slight bubbling to it. No water spewing out or anything - just like a bubbling that you might hear after putting soap on a tire with a pinhole leak. It is by far the shortest run from the boiler, and it does not happen all the time, so naively I figured it was some water coming with the steam. I am thinking that is a piping issue now! Is this something that I need to have addressed, and re-piped - or do you think we can make it functional for now?

    Seems like mains need to go - I think they are vent-rite something or other - so I will look at Gorton's or the Barnes that you mentioned. I assume this is just a matter of removing the old - and putting Teflon tape/re-installing the new? Anything else I need to be aware of here? Is the thread/pipe sizing the same, or is an adapter needed? This should help the steam reach the radiators more evenly and quickly?

    As for the pressure, here is a more clear picture of the pressuretrol. I have not adjusted any of this yet. I am not sure what you mean by internal setting, so maybe you can elaborate on that a bit. It makes sense in my mind that more pressure - would not allow for a long enough time for the water to come back, and thus leave the steam to push the water forward again - causing banging and all sorts of fun noises.

    I had feared the pitch of the piping under the floor, since it was an addition and the people who put it in might not have know as much about steam. I was fearing ripping the floor up to get to that pipe - but I like your suggestion quite a bit better. So if I was to do that I would raise the whole radiator slightly and then raise the side farthest from the supply slightly more, correct?

    I know this was long - and I had to type it twice since the first one vanished, but thank you all for your help!

    Warm Regards,


  • FredFred Member Posts: 6,312
    yes, turn the screw on top of that Pressuretrol and turn that indicator on the scale down to .5. Then take that one screw, on the bottom front of that box, in your picture, off and lift the cover off. You will see a white wheel on the floor of that box. Make sure it is set to "1" facing the front of the box. When a boiler runs for a long enough cycle, the pressure can build to a point where the water can't return to the boiler. It can be held in the radiators or the piping and cause the problems you are experiencing. That condensate needs to return to the boiler, both while steam is being supplied and after the boiler shuts down.
    The Barnes and Jones Bigmouth vents vent about twice as fast as the Gorton #2 and cost the same. I prefer the Bigmouth. They are built like tanks. They require a 3/4" tapping, which is what you have. The Gorton #2 requires a 1/2" tapping so you will need to use a bushing and bush that tapping down from 3/4" to 1/2".
    You aren't really blowing down the boiler from that drain. You havea probe type LWCO so blowdowns aren't required but if the water is muddy, after this heating season, it's a good idea to open that drain valve, drain all the water out, refill it and drain it a couple times to flush as much crud out as possible. After that fill the boiler back up to its normal level.
    Copper piping on the near boiler piping isn't great, except below the boiler water line and that smaller pipe that feeds the larger steel main isn't ideal either but I suspect if you get the pressure down and make sure the supply pipes are pitched correctly, that you can run pretty well until you either decide to have the boiler repiped or until the boiler needs to be replaced.
    Remember, a steam boiler is virtually silent. If you hear a lot of banging/hammer, water is sitting somewhere in the area of that noise. Bubbling and gurgling also means water either can't get out of a radiator or pipe pitch is incorrect.
  • ImYoungxDImYoungxD Member Posts: 33
    edited February 28
    Buy the Big mouths at Amazon. It's $75 with 4 in stock. The main vent you have is 3/4 which is the same size as big mouth should have no issues. Just add teflon tape. However, I suggest adding another pipe above so the main vent is located higher (like this This prevents debris and dirty water getting into the big mouth. I have one myself and saved a lot of time heating up my rads.
    I don't know how close your main vent is to the wood but you may not have room. I suggest copying this image

    As for the pressuretrol, the screw on top will adjust the cut in. Lower that down to 0.5. Don't go too far or the screw will get loose.

    As for the differential, you can find that by removing the cover by unscrewing the front. You'll see a white knob which can be adjusted down to 1.0
  • jkevinholmesjkevinholmes Member Posts: 20
    Thank you both again - so turn the power off, adjust the pressuretrol and then turn the power back on?

    Now there are only two of those vents left ... cause I snagged two of them! Got to love Amazon Prime!

    I will update when I get home with System Pressure ... etc!

    Not that I am questioning you guys at all - but 1900 square feet, and 9 radiators should be good with that pressure I assume.

    What is meant by add piping, just a piece 3/4 piping to raise it up to keep debris out?

    Thanks again!
  • BobCBobC Member Posts: 4,758
    Single pipe systems run best at low pressure, more than 1.5psi can cause issues.
    Steam vents sould be as high up as possible so they don't get hit by water sloshing back, that water may have rust and scale in it and you don't want that in the vent.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • FredFred Member Posts: 6,312
    edited February 28
    @jkevinholmes, The Empire state building runs on 2 or 3PSI. My home is 5000 sq. ft and runs on about 2 to 4 ounces of pressure. Low pressure is your friend. High pressure causes all kinds of problems and anything that runs above about 3 PSI can ruin all of your radiator vents.
    Also, you don't have to shut the power off to adjust the Pressuretrol. If it makes you nervous, you can.
  • JUGHNEJUGHNE Member Posts: 4,144
    I have 2 fair sized churches pushing 10,000 sq ft that heat on 4-8 ounces. With that control you have you can not set the pressure too low.

    A good weekend project would be checking the brass/copper pigtail under that pressure control.
    With power off and boiler cool unhook the 2 wires and unscrew the control off the pigtail. Do not take the four screws out of the bottom of the control. You must unscrew the hex fitting with a wrench and maybe a pliers on the tubing.
    A simple way to check for blockage is to simply "kiss" the top and blow thru it. If it feels clear you are good to go. If resistance then unscrew the pigtail from the boiler and flow water thru it.
    In either case you need to prime the trap of the pigtail with water. You should hear it run into the boiler as you add water.
    A clear pigtail is critical to good operation of the system.

    The better venting you have on the main the less short cycling on pressure you may have.
    Your pressure gauge will not give you an accurate reading of the boiler operation. It might just lift off zero. Eventually you can upgrade that to a 0-3 or 5 PSI gauge.

    Good news is that your boiler might not be too much oversized for your house. We see some that are 2 or 3 times too big.

    Also it would be good to drain the other valve on the wet return, the red handle valve. Drain out about 1-2 gallons. That is the low spot of the return water and will collect dirt there. If you flush it out then there would be less junk going into the boiler.
    You may have to top off your water level after.

    Also whenever you add a considerable amount of water or drain and flush the boiler you should bring that water up to boil to drive off the oxygen from the fresh water.
  • jkevinholmesjkevinholmes Member Posts: 20
    Small update, I believe I was able to turn down the pressure, pictures attached, but it was hard to determine the diff settings, I assume it is right the way it was! I also took a sight glass pic to show the debris and the water level!

    Let me know if this pressure setting looks right!


  • FredFred Member Posts: 6,312
    Yes, Pressuretrol looks like it is set right. Gauge glass could use a cleaning but the water looks clean. See if turning that pressure down resolves the gurgling and water noises. If not, move to the next step, raising the radiator a bit and repitching it.
  • New England SteamWorksNew England SteamWorks Member Posts: 950

    This radiator is on the longest run in the house and in an extension that was added in 2011 or so. I am sure this was not part of the original systems design.

    1. Undoubtedly, this radiator was piped wrong. Send pictures.
    2. You need much better main venting.
    3. But nothing will help until you lower the return connection to below the waterline:

    Serving Rhode Island & Eastern Massachusetts
    Old Houses & Steam Heat Our Specialty
  • jkevinholmesjkevinholmes Member Posts: 20
    Ryan right? I had emailed you but got super caught up at work recently!

    This is the troubled radiator in the addition.

    As you can see they used loose change to boost the legs, and the level seems to be towards the supply at a reasonable pitch.

    You can also see it probably needs a different vent.

    Does anything jump out at you?
  • jkevinholmesjkevinholmes Member Posts: 20
    I also got two Barnes and jones big mouths for the main vents, and they should arrive by Friday, so hopefully I can get those in this weekend!
  • Neild5Neild5 Member Posts: 57
    The Big mouths use a 5/8 Allen wrench to install, if you do not have one you can go to the hardware ststorend get a 7/16 bolt and nut with a washer and use that to tighten the fittings.
  • New England SteamWorksNew England SteamWorks Member Posts: 950
    What I meant about the radiator being wrong was it's piping from the steam main. Need pics of that.

    If you're in our service area drop a line and we'll lower that return tee and install your Big Mouths and you might be all set.
    Serving Rhode Island & Eastern Massachusetts
    Old Houses & Steam Heat Our Specialty
  • jkevinholmesjkevinholmes Member Posts: 20

    Unbelievably helpful information - I could not be more thankful!

    Update from this morning. No noises woke me up, which is a big plus. My wife gets up around 4:30/5AM and she said the system was certainly not silent, but not like it was the day before and only lasted a few moments. I will take that as a guarded, small, victory! I asked her to wake me up tomorrow to hear it - so I can provide more insight. Was not able to get a Pressure rating as by the time I got home the system was off already - will try again today.

    I had always thought that the mains would be the furthest point in the run - away from the boiler - but mine are literally above my boiler - but I suppose that is ok!

    What is meant by an Allen wrench required to install the big mouths. I would have thought you could just tape and install with an adjustable wrench, so I am happy that you brought that up. Is there a link to install instructions? Or any insight on how to go about that would be great. I am also hoping to add some piping as suggested, so recommendations on what piping / sizing / design would be great as well! Is this just 3/4" threaded pipe? I have some room it seems, but the new vent will be larger than the current vent-rites - so I should probably wait to see when they get delivered - especially given their close proximity to each other. Picture of location - and space above attached.

    @New England SteamWorks I sent along a message regarding the tee movement. I will get some pictures of the supply piping in the basement, so hopefully that will help!

    @JUGHNE That pigtail project sounds relatively manageable, maybe I should make this a heating weekend and do that as well! I am a little unclear on a few instructions, but I am sure there is a post in existence about how to do that, I will search.

    I have considered removing all radiator vents and soaking them - and eventually replacing them, would this be a recommendation you guys would make? I am not even sure what types are on each radiator - so maybe as I go I can take pictures and ask for recommendations on replacement vents if needed? I need a fire sale on some of those - because I would assume a few will need to be replaced.

    Thanks again - for helping me on this journey!


  • GrallertGrallert Member Posts: 211
    Not that I am questioning you guys at all - but 1900 square feet, and 9 radiators should be good with that pressure I assume.
    Just for comparison I am able to heat just over 95,000 sq ft with just under 2 psi.
  • jkevinholmesjkevinholmes Member Posts: 20
    :) just wanted to triple check as someone who really does not know much about the in's and out's of the process!

    I will admit I feel sort of silly having done so - but I learned!
  • ImYoungxDImYoungxD Member Posts: 33
    edited March 1
    See this video to clean pigtail. Starts at 2:00
  • GrallertGrallert Member Posts: 211
    It's good to question
  • FredFred Member Posts: 6,312
    @Grallert , we all agree. We were advising him to turm the pressure down from 5PSI (4 PSI Cut-in + 1 Diff).
    @jkevinholmes , when you get the Big Mouths, you will see it is a 2 part unit. You screw the base into your pipe tapping using the allen wrench on the hex inside that base and then you screw the vent onto that base with the union. It makes installation very easy and eliminates the need to have enough clearance to turn the entire vent.
  • jkevinholmesjkevinholmes Member Posts: 20
    @Fred That makes sense .. so the "hole" of the interior of the bottom fitting is essentially the 5/8 Allen wrench. You use the allen wrench to tighten that piece into the pipe tapping, then you screw the actual vent on top of that. It is almost like a coupling?
  • FredFred Member Posts: 6,312
    @jkevinholmes , That's exactly right
  • JUGHNEJUGHNE Member Posts: 4,144
    You do not to take the bottom off of the pressure control as shown in that video. It is best to unscrew it off the pigtail.
    If impossible then you could cut the pigtail with hacksaw.
    They are cheap, even the copper ones which are preferred.

    Taking that pressure control apart like could throw it out of calibration more than they already are.
  • FredFred Member Posts: 6,312
    I hadn't watched that video. Jughne is correct. Do not disassemble the Pressuretrol. Unscrew it from the pigtail. If you disassemble it like they did in the video, there is a loose pellet centered in that diaphragm that will either fall out and be lost or will be very difficult to get properly positioned when reassembling.
  • jkevinholmesjkevinholmes Member Posts: 20

    Update from this morning, seems to have been really quiet (no rushing water) aside from some faint knocking sounds, that also seem to be less then we have experienced in the past... and the room is still warm, so all and all - positive!

    My vents get delivered today so I will hopefully get those installed tomorrow along with attempting to remove/investigate the pigtail.

    What pipe size / composition would you recommend to get the mains higher than they are?


  • FinishGuyFinishGuy Member Posts: 17
    I’m not a pro, just a HO with steam heat and curiousity. The real masters will weigh in, but it appears to me like you have enough distance (the elbows help too) between the T-fitting at the drop of the dry return and your vents. Judging by the depth of your joists, you haven’t much room to gain vertically. I would just swap out the old for the new. You may have to tweak the horizontal arms of your vent runs side to side a bit to allow clearance for the new vents.

    1916 two-family, now condo. Top floor. 970 sq. ft. of ‘well ventilated’ space. One-pipe, parallel flow, gas fired steam heat. 27’ of 2” main (un-insulated) vented via Gorton #2. 27’ 1 1/2” dry return (un-insulated) vented by Dole #5. 7 HB Smith Princess 2 col. radiators (38” tall) & 1 ARCo 30s era thin-tube 6 x 8 sec. (32” tall) = total radiator EDR 244. Using Maid-o-Mist radiator vents, sized by calc. & 14 winters tinkering. 1980 HB Smith G210-S-5 rated output 120,000 btu, poor near boiler piping.
  • FinishGuyFinishGuy Member Posts: 17
    Perhaps it is obvious, but if not...

    1916 two-family, now condo. Top floor. 970 sq. ft. of ‘well ventilated’ space. One-pipe, parallel flow, gas fired steam heat. 27’ of 2” main (un-insulated) vented via Gorton #2. 27’ 1 1/2” dry return (un-insulated) vented by Dole #5. 7 HB Smith Princess 2 col. radiators (38” tall) & 1 ARCo 30s era thin-tube 6 x 8 sec. (32” tall) = total radiator EDR 244. Using Maid-o-Mist radiator vents, sized by calc. & 14 winters tinkering. 1980 HB Smith G210-S-5 rated output 120,000 btu, poor near boiler piping.
  • jkevinholmesjkevinholmes Member Posts: 20
    @FinishGuy I see exactly what you are saying. Essentially the goal is to get above those "tee" connectors where the return comes back, as high as possible to eliminate the potential of sediment clogging the vents. The previous person already did that by adding that additional piping so ... much more might not be required. Am I understanding that correctly?
  • FinishGuyFinishGuy Member Posts: 17

    Again, by my amateur eye, just change the vents because the existing piping looks fine. Easier too.

    But let’s see what the trained eyes have to say, when they get home from work, etc...

    1916 two-family, now condo. Top floor. 970 sq. ft. of ‘well ventilated’ space. One-pipe, parallel flow, gas fired steam heat. 27’ of 2” main (un-insulated) vented via Gorton #2. 27’ 1 1/2” dry return (un-insulated) vented by Dole #5. 7 HB Smith Princess 2 col. radiators (38” tall) & 1 ARCo 30s era thin-tube 6 x 8 sec. (32” tall) = total radiator EDR 244. Using Maid-o-Mist radiator vents, sized by calc. & 14 winters tinkering. 1980 HB Smith G210-S-5 rated output 120,000 btu, poor near boiler piping.
  • FredFred Member Posts: 6,312
    It looks fine to me. Those vents do look like they are about 6" above the return and also offset to the side. Just replacing the vents should be fine.
  • jkevinholmesjkevinholmes Member Posts: 20
    edited March 3
    Ok all, just was down in the basement assessing the vents, and the system went on while I was down there. BIG MOUTHS were delivered today!!!

    So pretty quickly the pressure gauge gave the attached reading and the system turned off shortly after. From what I have learned

    A ) that pressure gauge is a bad indicator since it goes 0-30
    B ) isn’t 7 psi really high for what I need?

    Granted the temp was at 70 when I went back upstairs, which is what it is set to, but why would the system fire for only ~7 minutes or so? Is the system seeing that pressure as too high and cutting it off? Doesn’t that seem horribly inefficient?

    I went upstairs and about 5 minutes later it fired up again, even though the thermostat is already at 70.

    Hopefully I can get this all squared away so I can stop bugging you nice folks!!

    Thanks as always!!

  • FredFred Member Posts: 6,312
    edited March 3
    - Did you clean that pigtail out? It may be clogged.
    - That Pressure gauge may be defective. You should install a 0 -3 PSI Gauge on the same pigtail (with a Tee) as the Pressuretrol is mounted on.
    - That is a programmable thermostat. Has it been programmed for steam, 1 or 2 cycles per hour? They come from the factory with a default setting for forced air at 5 cycles per hour.
    - If you clean the pigtail and put a new low pressure gauge on the boiler and the pressure is actually that high (which I doubt, in that short of a heating cycle) I can post the precedure to re-calibrate the Pressuretrol.
  • FredFred Member Posts: 6,312
    Here is the link to the gauge that many of us use on our boilers:
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