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Radiator sounds like it is boiling water inside of it

I have one radiator, the furthest from the boiler that upon initial startup (once steam starts getting to it) sounds like it boiling water or sounds kinda like rain dropping. If I go downstairs to the 1st floor I can also here it in the wall where the pipe is leading up to it from the main in the basement. It almost sounds like water rushing down the pipe. After it gets warmed up it pretty much stops. This happens each heating cycle. I had all the vents replaced and am aware that the new boiler is a bit over-sized. The pitch is good I believe. I am just no sure what to try or do next. Any suggestions would be greatly appreciated. Also is there a guide floating out there referencing proper vent size in regard to position or distance from the boiler? thanks!

Comments

  • ethicalpaulethicalpaul Posts: 1,336Member
    OK so it's a 2nd floor radiator, right? Do you know the EDR of it, or can you post a picture?

    Do you know the size of the pipe that is supplying steam to it?

    Is there one pipe or two going to the radiator? If there's one (which I suspect because you mentioned vents), then what size vent is on the radiator?

    And as I re-read your post, let me ask this: What is the complaint? Just the sound? Radiators make water out of steam, so this behavior is expected, as long as it's not causing heating problems, this might be as designed. Does it keep the room warm?

    You said you think the pitch is good. Why do you think that?
    1 pipe Utica 112 in Cedar Grove, NJ, 1913 coal > oil > NG
  • Jamie HallJamie Hall Posts: 11,857Member
    It probably is water rushing down the pipe And if you only hear it when steam is rising, and not so much when the system is really heating along, it's probably from condensate forming in the feed pipe itself. One way to reduce that is to insulate that riser, if you can.
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • BobCBobC Posts: 5,056Member
    There could be a horizontal pipe just under the floor that does not have enough pitch. Try using a 2X4 and a block to lift the whole radiator up and then shim everything up with strips of plywood under the legs. Use a level to make sure the radiator has some pitch so water can find it's way out.

    I found using a 3/4" strip of plywood under the vent end and then a 1/2" strip under the supply end worked well for me. If that helps but doesn't stop the noise you may have to go a bit higher. When lifting be gentle, you won't want to force anuthing.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • JUGHNEJUGHNE Posts: 6,438Member
    One thing you could try first is to switch off the boiler just before it would usually turn on, then go to that radiator and unscrew/remove the air vent. See if you feel air being sucked into the vent hole and hear the water running down the pipe.
    At this point, just before the boiler would start, the radiator should be fairly cool so there should be no concern about burning yourself.

    See what happens and then replace the air vent and turn the boiler back on.
    Let us know, thanks.
  • Hap_HazzardHap_Hazzard Posts: 1,930Member
    I think @BobC nailed it. I have one radiator that does this too. It's in a bathroom that we remodeled a couple of years ago, so I got to see the cause, but, unfortunately, there's nothing I can do about it. This bathroom is part of an addition to the house that was done back in the 60s, and they ran the supply pipe under the bathroom floor, where they weren't able to give it enough pitch, and I didn't see any way to improve on it, so I decided to just live with it.

    What's happening is that, while the radiator is filling, and the condensate starts pouring out, the water in the pipe gets deep enough for the steam to whip up waves. The waves don't seem to get big enough to form water pistons, so there's no actual steam hammer, but while the vent is still open, you can definitely hear the ocean in there.

    Hopefully you'll be able to see some improvement from raising the radiator, as Bob suggests, but unless it gets worse, at least there's nothing really harmful going on.
    Just another DIYer | King of Prussia, PA

    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Matthewdg73Matthewdg73 Posts: 28Member
    edited January 9
    Thank you for replying below are my responses to your questions.

    OK so it's a 2nd floor radiator, right? Do you know the EDR of it, or can you post a picture?
    I don't have a pic I can post at the moment but the dimensions of the radiator are as follows:
    columns-4
    sections-30
    height-22"
    width-44 1/2"


    Do you know the size of the pipe that is supplying steam to it?
    the pipe branching off the main (2") is 1" that leads into the radiator.

    Is there one pipe or two going to the radiator? If there's one (which I suspect because you mentioned vents), then what size vent is on the radiator?
    its a one pipe system

    And as I re-read your post, let me ask this: What is the complaint? Just the sound? Radiators make water out of steam, so this behavior is expected, as long as it's not causing heating problems, this might be as designed. Does it keep the room warm?
    The room definitely gets warm. Prior to the new boiler this did not occur.

    You said you think the pitch is good. Why do you think that?

    It has a slight tilt back to the valve. I am just assuming its good.
  • Matthewdg73Matthewdg73 Posts: 28Member
    JUGHNE said:

    One thing you could try first is to switch off the boiler just before it would usually turn on, then go to that radiator and unscrew/remove the air vent. See if you feel air being sucked into the vent hole and hear the water running down the pipe.
    At this point, just before the boiler would start, the radiator should be fairly cool so there should be no concern about burning yourself.

    See what happens and then replace the air vent and turn the boiler back on.
    Let us know, thanks.

    Will do that this evening and post the results. :)
  • Matthewdg73Matthewdg73 Posts: 28Member
    edited January 9
    Hap_Hazzard
    You nailed what it sounds like. :)
  • dopey27177dopey27177 Posts: 115Member
    Condensate removal from risers on 1 pipe steam systems can be problematic at times.

    It sounds like Jamie hall got that right.

    Here is a way to get rid of the condensate from the base of the riser and preventing it from running down the horizontal supply from the riser to the steam main.

    These drawings were take from my book "Steam The Perfect Fluid and Some of the Problems"

    Jake
  • ethicalpaulethicalpaul Posts: 1,336Member
    > The room definitely gets warm. Prior to the new boiler this did not occur.

    OK that’s good. What was the complaint though?

    And regarding pitch, I was referring to the pitch all along the runout
    1 pipe Utica 112 in Cedar Grove, NJ, 1913 coal > oil > NG
  • Matthewdg73Matthewdg73 Posts: 28Member
    edited January 10
    I guess my complaint would be the noise and if that was safe and nothing to worry about other than being a bit annoying waking up from it during the night. :smile:
    As far as the pitch from the runout I am not completely sure. The pipe running from the main has a noticeable gradual increased angled up until it runs into a vertical line running the length of the first floor to the second. (Best way I can describe it) From there, there might be a short horizontal run to the radiator but that is just an assumption as I do not have access to see for sure.
  • Matthewdg73Matthewdg73 Posts: 28Member
    edited January 10

    JUGHNE said:

    One thing you could try first is to switch off the boiler just before it would usually turn on, then go to that radiator and unscrew/remove the air vent. See if you feel air being sucked into the vent hole and hear the water running down the pipe.
    At this point, just before the boiler would start, the radiator should be fairly cool so there should be no concern about burning yourself.

    See what happens and then replace the air vent and turn the boiler back on.
    Let us know, thanks.

    Will do that this evening and post the results. :)
    JUGHNE
    so I took the vent off while the boiler was not running (hope I understood your directions correctly) and did not notice any air being sucked into the vent hole. What I did notice was that the vent had water in it. I made sure to empty that out.
  • JUGHNEJUGHNE Posts: 6,438Member
    The reason for the test is that on at least 2 systems I service there has been water trapped out in the system.....think of the water that stays in the straw that has your finger over the end of it as you pull it out of the glass.

    Some change in the system piping pressure/vacuum would then allow this water to suddenly return to the boiler.

    So then if that is not your situation, you are back to raising that radiator up on both ends (1/2-3/4") and shimming up the end opposite the inlet valve.

    A brainstorm I just had:
    Another possibility is that the rubber washer and/or disc has fallen off and is covering the opening into the bottom of the supply valve. The steam will pass thru but not allow the water to drain back and the rad partially fills with water. The disc then acts as a check valve flap and when the steam coming up lifts the flap allowing the water to drain. This would usually be causing water hammer at that rad. Just a WAG
  • Matthewdg73Matthewdg73 Posts: 28Member
    JUGHNE said:

    The reason for the test is that on at least 2 systems I service there has been water trapped out in the system.....think of the water that stays in the straw that has your finger over the end of it as you pull it out of the glass.

    Some change in the system piping pressure/vacuum would then allow this water to suddenly return to the boiler.

    So then if that is not your situation, you are back to raising that radiator up on both ends (1/2-3/4") and shimming up the end opposite the inlet valve.

    A brainstorm I just had:
    Another possibility is that the rubber washer and/or disc has fallen off and is covering the opening into the bottom of the supply valve. The steam will pass thru but not allow the water to drain back and the rad partially fills with water. The disc then acts as a check valve flap and when the steam coming up lifts the flap allowing the water to drain. This would usually be causing water hammer at that rad. Just a WAG

    How would I go about checking the rubber washer idea you suggested could be a possibility?
  • Matthewdg73Matthewdg73 Posts: 28Member
    I have had water hammer on that main before. Not sure what I did to resolve it but haven't had it happen in a while.
  • Hap_HazzardHap_Hazzard Posts: 1,930Member
    edited January 10
    That water hammer was probably what's called differential shock (by nerds). It happens when the liquid phase in a biphase flow system (water in a steam pipe) gets deep enough to allow the gaseous stream (high velocity steam) to propagate waves that reach the top of the vessel, forming a water piston. Once the water fully obstructs the pipe, the stream pushes it forward at a high rate of speed, picking up additional water as it goes, until it reaches the end of the vessel (in this case, your poor radiator). When you have a heavy liquid moving at a high velocity, it can do real damage.

    BTW, have you had your boiler skimmed recently? If you're getting an unusual amount of water up into your pipes and radiators, sometimes this helps.
    Just another DIYer | King of Prussia, PA

    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • JUGHNEJUGHNE Posts: 6,438Member
    Matt, to check inside that supply valve you can unscrew the top bonnet which is under the packing nut that the handle stem passes thru. This can be challenging as it has been together for a long time.
    The next method is to loosen the union nut that connects the valve to the radiator.....the rad is very heavy and may be top heavy to tip over so use caution. With the rad disconnected you can slide it away from the valve and check inside....operate the valve to see what moves up and down. The disc should move up quite a bit and expose the opening down into the supply pipe. If the disk or washer is laying there not moving remove it if possible.

    If that is the case and you get that removed, just reconnect the rad. A little wiggle on the rad as you tighten the union nut.
    It must be aligned correctly to get a good seal.
    Don't worry about not having a working valve as it should be completely open or closed. And with age they seldom close completely and give the problems you have now.

  • Matthewdg73Matthewdg73 Posts: 28Member

    That water hammer was probably what's called differential shock (by nerds). It happens when the liquid phase in a biphase flow system (water in a steam pipe) gets deep enough to allow the gaseous stream (high velocity steam) to propagate waves that reach the top of the vessel, forming a water piston. Once the water fully obstructs the pipe, the stream pushes it forward at a high rate of speed, picking up additional water as it goes, until it reaches the end of the vessel (in this case, your poor radiator). When you have a heavy liquid moving at a high velocity, it can do real damage.

    BTW, have you had your boiler skimmed recently? If you're getting an unusual amount of water up into your pipes and radiators, sometimes this helps.

    I have skimmed it on multiple occasions and have noticed a huge difference in the color of the water in the site glass (muddy brown to almost clear) and the company that installed it in June 19 will be coming out tomorrow to skim it as well. Needless to say I think the company that installed the boiler did a poor job all around and I will be watching them with hawk eyes.
  • Matthewdg73Matthewdg73 Posts: 28Member
    JUGHNE said:

    Matt, to check inside that supply valve you can unscrew the top bonnet which is under the packing nut that the handle stem passes thru. This can be challenging as it has been together for a long time.
    The next method is to loosen the union nut that connects the valve to the radiator.....the rad is very heavy and may be top heavy to tip over so use caution. With the rad disconnected you can slide it away from the valve and check inside....operate the valve to see what moves up and down. The disc should move up quite a bit and expose the opening down into the supply pipe. If the disk or washer is laying there not moving remove it if possible.

    If that is the case and you get that removed, just reconnect the rad. A little wiggle on the rad as you tighten the union nut.
    It must be aligned correctly to get a good seal.
    Don't worry about not having a working valve as it should be completely open or closed. And with age they seldom close completely and give the problems you have now.

    If I do the top bonnet method do I need to have any packing ready to put back in once I put it back together? I know just enough to get me into trouble. Still wet behind the ears :)
  • JUGHNEJUGHNE Posts: 6,438Member
    How about a picture of the valve and another of the rad full view?
  • neilcneilc Posts: 752Member
    one more thing or two,
    boiler pressure ?
    and,
    it was written just recently in another thread,
    if the rad is venting too fast, it might be the steam shooting up colliding with the condensate falling back down, gurgling,
    you said the rad definitely heats,
    as in too much?
    might try slowing that rad's venting.
  • Matthewdg73Matthewdg73 Posts: 28Member
    JUGHNE said:

    How about a picture of the valve and another of the rad full view?

    Sorry, I have been out of the loop for a few days. Will get pics this evening and upload.
  • Matthewdg73Matthewdg73 Posts: 28Member
    neilc said:

    one more thing or two,
    boiler pressure ?
    and,
    it was written just recently in another thread,
    if the rad is venting too fast, it might be the steam shooting up colliding with the condensate falling back down, gurgling,
    you said the rad definitely heats,
    as in too much?
    might try slowing that rad's venting.

    Yes the rad gets very hot. The warmest room in the whole house I believe. We have to open a window at night to let out some of the heat.
  • neilcneilc Posts: 752Member


    Yes the rad gets very hot. The warmest room in the whole house I believe. We have to open a window at night to let out some of the heat.

    So I think you want to slow this rad down venting wise,
    less air and steam rushing up that riser, less collision with condensate trying to get back down,
    slow it down to where the rad only gives off enough heat, and to where you can keep that window shut.
    see if that doesn't stop the gurgles and boiling.
    I don't think you don't say what vents are here, or elsewhere,
    and I can't quote which vent is which speed wise,
    post a picture, or two, and some of the other guys can advise.
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