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Radiator is terribly noisy. Hope you can help me get some sleep!

Hi All,
We have a 1 pipe steam system in an old small apartment building. Recently our bedroom radiator started making a kind of bubbling or whooshing noise. I suspect the boiler is kettling. I'm not sure it's related but the boiler has a really short cycle of 2 minutes on and 2 minutes off 24/7 while it is cold outside (it only has an outdoor thermostat to control it). When it's warm enough and the boiler turns off for a few hours during the day the bubbling noise goes away until the next morning.

I was hoping you guys had some advice for how to approach getting the noise to go away so we can sleep again!

There is a video at this link so you can hear it.

https://photos.app.goo.gl/iRCKR3yhVM2DPD6t8


Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,350
    If this is an apartment building you probably don't have control over the whole system. Is that correct?

    Get a level and make sure the offending radiator is pitched lower on the valve end. Use a crowbar and some wood blocking and some shims to pitch it in the right direction.

    If this doesn't work try raising the valve end 1/4" and then the far end a 1/4" to maintain the pitch. Gently

    Hope this works
    corey_denver
  • corey_denver
    corey_denver Member Posts: 10
    edited January 2021
    It's a condo in a small HOA and I am 1 of 3 on the board so I have some say into what is done with the overall system.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,613
    The pressure in the system may be set too high. The cycles on the burner are also too short. The noise in your radiator can only be addressed in the boiler room as far as I can tell.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    corey_denver
  • corey_denver
    corey_denver Member Posts: 10
    Thanks Ed. The cut-out on the vaporstat is 1.5 psi and the cut-in is 16oz (subtractive diff).
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,613
    The steam is traveling quite fast near that valve for that noise. Is your radiator on a tee near the boiler, or is your radiator near the end of the main? If you are close to the boiler room, then the main piping size may be too small for the amount of steam flowing therein. This may not be repairable without a major repiping of the steam main.

    There are others on this forum with more steam experience. They will need more info from the boiler room. A picture of the boiler room piping and maybe a diagram of your radiator location in reference to the steam main running thru the building. Main pipe size at the boiler and at the branch tee where your radiator is located on the main.

    Difficult to diagnose without more info.

    Yours Truly,
    Mr.Ed
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    corey_denver
  • MilanD
    MilanD Member Posts: 1,160
    Is the radiator getting adequately hot while you are hearing this sound? Is this the only radiator giving off this type of noise? Are other neighbors having similar issues with any of their radiators? Is the house/apartment otherwise warm enough when this is happening?

    Also, you mentioned a few other facts which are relevant:

    1. Outdoor reset/sensor/thermostat control (there is some kind of indoor sensor too, btw).
    2. Radiator does this noise only when it's very cold outside.
    3. You hear the boiler going 2 min. on/2 min. off when this is occurring, and it is occurring only when the boiler is on/off for 2 minutes 24/7 on a cold day, and not in any other scenario.
    4. Rad does not do this from the cold start on a warmer day (boiler off for a few hours).

    To my ear, if the radiator is hot, this sound is a typical cycling on pressure sound (like water running a water main - except you are hearing steam). That is, the system is heating to its max, the radiators are fully hot, yet the burners come on again and are forcing pressure into the full system without waiting for the heat do dissipate from the hot radiator (think sound of a fully inflated balloon, and you trying to push more air in it). Please confirm this is the case.

    I would check few things:

    1. Outdoor/indoor reset/thermostat may need to be adjusted to longer wait time between cycles on a cold day, may have gone bad, or perhaps a delay switch needs to be installed to correspond with the lower outdoor temps if this can't be adjusted on the outdoor reset thermostat itself.
    2. Pressuretrol may have gone bad and allows for higher op pressure (maybe).
    3. Someone with a right-turn-only screwdriver has messed with the pressuretrol and turned up the pressure.
    4. On especially cold day, modern controls may only look to satisfy the algorithmically preset indoor/outdoor differential temp, and with the very cold day, this temperature difference may cause the "computer" to not compute quite correctly. Which outdoor control is used on the system?

    The only other thing I can think of that can be doing this - is broken/detached disc on the shut-off valve bonnet, on the rad valve itself. If this is the case, the rad would heat poorly, and after a few cycles it would get waterlogged and you'd get water squirting out of the vent. I'm assuming this is not the case.

    I hope this helps.
    corey_denver
  • corey_denver
    corey_denver Member Posts: 10










  • corey_denver
    corey_denver Member Posts: 10
    edited January 2021
    @MilanD

    The radiator is hot when the sound appears. We do close the valve most of the time because the system never turns off so it would be ridiculously hot if we didn't (the sound is still there when it's closed). I suspect most residents do this. In fact the two apartments below are empty so the valves are probably closed in those bedrooms.

    When it's cold outside (below like 60F so I guess cool really) they system never stops the 2 min on/off cycle. Looking at the control wiring I really think there is only an outdoor thermostat on the system and that thermostat is dumb and is either on (below 60) or off (above 60) and the two minute cycles is the vaporstat.



  • MilanD
    MilanD Member Posts: 1,160
    edited January 2021
    @corey_denver

    Wow, I think you guys must have a huge heating bill if that thing never stops and cycles on pressure 24/7 whenever outdoor temp is below 60... Wow.

    Closing down the rads also, technically, oversizes the boiler, and that's where all these problems are compounded. 

    You need to get rid of the "dumb" thermostat/outdoor reset thing and connect it to some other set-up. There are these smart Honeywell or whatever they are called wireless and fancy round things that are capable of averaging out the various temps in the building and would calculate how long to run the boiler. That being said, I don't know what would really be the best, but whatever it is, it can't be worse than what you have now.

    Or, just get a regular tstat and put it in the coldest room.

    If I were you, my first order of business would be to remove that fuel-guzzling setup. 2nd is to open all the rads in empty rooms. Closing them makes the problem worse. You are cycling on pressure and that is why you are hearing the "whooshing" sound in your radiator. And it's even. worse if you close the valve.

    If you are too not, just throw a blanket over the radiator. It's better than closing it off.

    I think any reputable company with experience in steam should be able to get you squared away quickly, with a new tstat, and a bigger mechanical company that has someone who is in charge of or is familiar with the steam process controls can figure out how to upgrade this crude outdoor switch to a newer one. Lastly, on a cheapo, you can wire in a delay switch in the current set-up, and this should allow you to set up cycles on every 10-15-20 min, or whatever. Heck, you can set it up in your own unit and use the delay switch as a thermostat. But, I'm getting exotic... Get a better controller i.e. new tstat.

    Where are you located?  Look at pros who advertrize here, or post a question asking for recommendations if none here are in your area. Or just call whovere is now maintaining your system and ask them.

    Good luck!!

  • Jamie Hall
    Jamie Hall Member Posts: 22,969
    It probably is cycling om the vapourstat. An uncommonly miserable and inefficient arrangement.

    The boiler piping is somewhat dubious, but you could probably save yourself and the rest of your people a good bit of cash if you got someone familiar with steam heat in there just to revise the controls to something which made more sense.

    You might be able to find someone in the "Find a Contractor" tab above -- or just simply tell us where you are, and we may know someone.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • corey_denver
    corey_denver Member Posts: 10
    Thanks for all the suggestions guys!
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,613
    I see a 6” boiler supply tapping reduced to 4” riser then a 4” main with a 2” equalizer. The piping is minimum for a 211A-04, but it appears the the boiler is bigger than that. The velocity noise is not going away any time soon. The main is too small for the amount of steam that boiler can produce.

    If the HOA can agree on a steam expert evaluation of the control system, you may get some relief with cycling the boiler off once all the apartments are satisfied. It won’t be cheap but it may pay for itself in fuel cost saving. And perhaps the pressure will drop if you can get an off cycle from time to time.

    Yours truly,
    Mr.Ed

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • corey_denver
    corey_denver Member Posts: 10
    I really appreciate you taking the time to make the comments here Mr.Ed. With the help of the posts of you and Jamie and MillanD I will convince the HOA to get someone in here to help us straighten this thing out.
  • JUGHNE
    JUGHNE Member Posts: 11,021
    There is more.....looking at the flue pipe (round exhaust/smoke pipe).

    It looks like 10" leaving the boiler, then reduces to maybe 6" and then runs downhill!

    Show us where that round pipe connects to a chimney please.

    This looks to be a very dangerous situation for flue gas venting, IMO.
  • corey_denver
    corey_denver Member Posts: 10
    edited January 2021
    That is the venting to the hot water heater. From the heater to the chimney which is behind that. We are big enough that we get inspected by the city and the inspector said the system is safe. So at least is does that right haha.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,613
    edited January 2021
    JUGHNE said:

    There is more.....looking at the flue pipe (round exhaust/smoke pipe).

    It looks like 10" leaving the boiler, then reduces to maybe 6" and then runs downhill!

    Show us where that round pipe connects to a chimney please.

    This looks to be a very dangerous situation for flue gas venting, IMO.

    I thought the same thing until I got a closer look at the picture. The small pipe must be fron another appliance like s water heater or something

    You can see the chimney connection just behind the boiler where the increaser fitting connects to a larger tee fitting like 14”.

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • corey_denver
    corey_denver Member Posts: 10
    Just following up, we figured out what the noise was. The downstairs apartment has been vacant and they closed radiator service valve but not all the way...
    ethicalpaul
  • mattmia2
    mattmia2 Member Posts: 9,475
    You could probably still save quite a bit in fuel by installing a better control arangement and maybe looking at all the radiation connected to that beast and downfiring it to better match the connected radiation.