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Awaken every morning lately =(

HenryT Member Posts: 128

Hi all, I am in some desparate need of help.

I have rather large radiator that hammers and bangs very loudly when steam starts to heat it. The thing heats up fully and I have no other issues with it.

My problem is that the noise this this produces is really starting to annoy me and im starting to lose sleep in the AM with it because of the temp drop recently and now the boiler calling for heat earlier due to the temp recovery feature on t-stat from night setback.

The unit is about 2'-3" in height. Theres about 30+ columns on this radiator with 6 legs. Two on each end and two in the middle to support the heavy unit.

I just recently put a varivalve on this and had it on full venting because of the size of the unit.

Bang occurs when the unit starts to heat up across the middle sections of the unit.

I am lacking spacing on the top because unit is made to fit in a grove. I think I may have about an inch of headroom for shims.

Are there any other alternatives to rectifying the water hammer? The unit was fine last year until the installation of new valve. Am I venting too fast?

If I shim the end of the radiator, will the center collapse?

Please help or provide any info that may help me! Much appreciated!!!

Thanks in advance. </span>


  • Slower Venting

    Hi Henry-  A couple of things come to mind. Did the radiator make noise before you changed the vent to a VariVent?  VariVents are pretty aggressive.  I think I'd try slowing down the venting. When steam comes into a large cold radiator it condenses at a very high rate and the large volume of returning condensate (water) leaving the radiator collides with the steam rushing into the radiator, resulting in hammering, so the idea is to slow down a bit  the entry of steam into the radiator.  The other thing is you may not want to use too much setback on your thermostat. The consensus here seems to be that using more than a 5 degree setback uses more fuel making up the temperature than the setback saves.

    - Rod
  • HenryT
    HenryT Member Posts: 128
    Thank ROD

    Thanks Rod. i will try slowing the venting on the varivalve.

    the old valve was quiet before the installation of the new valve, so i know the problem had to be with the valve somewhere.

    do you think i need to prop up my radiator?
  • Shimming

    I'm not quite sure what you mean by "prop up"  On a one pipe system, the radiator should be slightly sloped towards the inlet pipe. To give you an idea of how much, I use quarters ($0,25) to determine how much shimming I need. All you want is enough slope to encourage the condensate (water) to go towards the inlet pipe. Too much shimming can cause problems.

    When I make a change I usually wait a day or so before doing something different (another change)  to the steam system, as that way you know which change made the difference.

    In this case I'd wait and see what difference  the slower made before doing any shimming.

    - Rod
  • HenryT
    HenryT Member Posts: 128
    Thanks ROD!

    I will try that approach.

    Can anyone recommend a few places for steam pipe insulation? I think this may be one of my problems, is that my mains are uninsulated.

    I tried searching the wall, but the new searches just dont come up with the expected results.

  • Jamie Hall
    Jamie Hall Member Posts: 22,912

    There are a lot of places, but I know State Supply has it -- just looked to check.  If your mains aren't insulated, they definetly should be.  May not be the source of the problem, but it surely isn't helping.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • jpf321
    jpf321 Member Posts: 1,568
    my big box home supply store

    has 3ft lengths of fiberglass pipe insulation for a few bucks each for 2in pipe. they don't have pieces for T's and El's only straight pipe. 
    1-pipe Homeowner - Queens, NYC

    NEW: SlantFin Intrepid TR-30 + Tankless + Riello 40-F5 @ 0.85gph | OLD: Fitzgibbons 402 boiler + Beckett "SR" Oil Gun @ 1.75gph

    installed: 0-20oz/si gauge | vaporstat | hour-meter | gortons on all rads | 1pc G#2 + 1pc G#1 on each of 2 mains

    Connected EDR load: 371 sf venting load: 2.95cfm vent capacity: 4.62cfm
    my NEW system pics | my OLD system pics
  • lutorm
    lutorm Member Posts: 78

    I just got my insulation from expressinsulation.com.
  • HenryT
    HenryT Member Posts: 128

  • HenryT
    HenryT Member Posts: 128
    will this work?

    All, i picked up 1" insulation and will be slapping them on this weekend hopefully things will work out.

    I have a weird question to ask before i execute and hopefully i can get your opinion.

    As mentioned, i have the rather large radiator in which i think has water inside from a flooding accident that occured.  (the unit never banged until after accident).

    Being that it is so big and so heavy, and assuming it is sloped towards the supply pipe, can i remove the water inside by using a pressure blower? I would just unscrew the radiator vent and use that opening to blow all pooled water down the supply pipe? will i cause any harm?

    Thanks for your opinion.
  • drain the radiator?

    if the radiator is setup properly, it will self-drain, so don't waste time with blowers and vacuums, etc.

    check the level [with a level], then correct, and see if it starts to drain. what was the accident of which you spoke?

    if your pressure is too high, it may prevent the vents from working properly.--nbc
  • HenryT
    HenryT Member Posts: 128
    Thanks NBC

    Pressure is currently regulated by my pressuretrol set under 2psi.

    I am cycling on pressure and exploring to downfire my boiler now. 

    as for leveling... this radiator never made ANY noise before the accident. It can be the new varivalve, but i dont think it can cause that much banging.

    Accident happened where the radiator was flooded with water. ever since, ive been hearing LOUD noises when steam hits this radiator. So i figure it drains, but there may be water pooled in middle due to flooding.  as for leveling, if it was not banging before, i assume the level is good. and plus this radiator fits exactly into a groove (about 1/2" open space) and i have very limited space for shims... thats why i am in the situation im in. as you can see i am desparate for solutions.

    how do i level big rads without its sagging in middle? do i have to shim the end with 3 quarters then shim the middle with 2 quarters? would i risk the chance of it cracking in half?

    Thanks again.
  • the silence of the radiators

    i am sure that the banging is caused by wet steam [clean waterline by skimming], or high pressure. 2 psi may seem pretty low, but a better pressure would be 8 ounces max [unfortunately unavailable with the standard pressuretrol]. i have now forgotten if your insulation, and venting are good, but a lack of either can contribute to water going places where it should not! water will rise 1.75 inches in the returns, for each ounce of boiler pressure, so the lower the pressure, the better! your pressure may be higher than need be because the standard 0-30psi gauge is inaccurate at the lower range, even when new.

    once the proper conditions have been restored, then the water usually can drain away.--nbc
  • HenryT
    HenryT Member Posts: 128
    Thank you.

    will respond with updates.
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