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Steam System (Raining Sound ?)

btc Member Posts: 43
I dont know if it is "rain" sound, but on start up, distinct "sound" in radiators that is transmit from boiler. At certain temp (about 5 minutes) sound goes away. This sound is in all radiators, then none...brand new peerless boiler Series 63. Never had sound before...


  • Rich Herring
    Rich Herring Member Posts: 2
    Raining Sound When System Heats Up


    I have a one pipe steam system. This year when the system starts to heat up, in one section of the house, I hear a raining sound (like a slow rain on your roof) coming from the radiators in that part of the house. I checked for water everywhere and didn't see anything.

    Thoughts ?


  • Paul Fredricks_3
    Paul Fredricks_3 Member Posts: 1,557

    When I think of rain on the roof, I think of a clicking noise. Is that what you mean, or more like a dripping or gurgling sound? Is it constant or does it come on slowly, speed up, then slow down and stop when the radiators are hot?
  • Cast Iron
    Cast Iron Member Posts: 35
    Me too!

    I have been thinking of way to describe it. Both our old boiler and new one do this. (One Pipe Steam) When the system first fires the boiler makes a 'raining' sound for the first 3-4 minutes. If you stand next to you boiler when it turns on you'll here that it is coming from there. As soon as it hits a certain temperature, it diminishes and goes away. It almost sounds like a pot of boiling water, just before it boils on the stove. Interestingly, when our new boiler was installed I didn't hear the noise initially, but then it appeared. Then when we skimmed and flushed, it disappeard, but was soon as that water was in the boiler for a couple cycles, the sound came back at startup.

    I am not an expert but perhaps it has to do with the presence or absence of oxygen in the water.
  • lee_7
    lee_7 Member Posts: 458

    If sound is like popcorn popping, sounds like you still have mud from pipes in system. could need to be flushed again.
  • Dave_4
    Dave_4 Member Posts: 1,405
    Me three?

    I have kind of a raining sound in one of my risers only (furthest one) at the beginning of the steam cycle and then it goes away. Seems odd to me that there is water stuck in this riser/the main that is then being pushed up by steam there but I can't bash open my wall to take a look at the pipe to see if there's a weird pitch problem somewhere. One other radiator has a weird gurgling/chugging sound even though the radiator is pitched right and I sometimes hear a very quiet water hammer towards the start of the steam cycle only, but only on one top floor radiator (and the water hammer is heard before steam even begins to reach the radiator itself).

    I've had Experts come out and look at it, but nobody has figured it so far. Too bad Steamhead doesn't do work out here, I'm sure he would have figured out what was wrong in about 5 seconds. :( I've kind of learned to live with it, but it would be nice for it to be perfect, it's so damn close. I almost wish I had a constant water hammer, it would be much easier to find than this one.
  • Long Beach Ed
    Long Beach Ed Member Posts: 1,188
    Raining Sound in Steam Radiators

    The sound you hear may be caused by the steam rushing through large amounts of condensate on startup.

    If it occurs on start-up mostly when radiators are cold, this is the cause. You may notice it especially if there is a horozontal pipe near the radiator.

    When the radiators are stone cold, and steam begins running into them, the steam very quickly gives up its heat and turns to condensate. The condensate comes fast and heavy at those times. If the volocity of the steam is great (if the radiator has a large vent on it for example), the rising steam will meet hte departing water sounding like a rushing fire hydrant.

    Once the system is warm and the iron radiator is no longer stone cold, condensate creation is slowed and the problem abates.

    If you extend the vent time of the radiator by instyalling a smaller (slower) air vent, you may be able to control or limit the problem.

    Long Beach Ed
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    I'd say you've answered your own question

    Flush and skim the boiler again.

    What's happening is that the boiler is receiving lots of dirt from the system. This must be allowed to work its way back and be flushed out of the boiler as needed. Keep at it, and eventually it will be gone.

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  • Rich Herring
    Rich Herring Member Posts: 2
    Raining Sound When System Heats Up (Fixed)


    Thanks, I fixed the problem. The radiator is in my kid's room and one of daughters must have fiddled with the valve in the summer. It was only 25 percent open. Once I opened it all the way, the sound went away.


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