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Baseboard Heat

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steve617
steve617 Member Posts: 13
in THE MAIN WALL

Why does the sound of baseboard heat change when the circulating water gets hot? Is it due to pressure increase on the pump?

Comments

  • psb75
    psb75 Member Posts: 1,142

    Can you be more specific about "the sound". Give some descriptive words about the sound changes and be more specific about the timing of the circulator, the boiler start and the specific type of baseboard (fin tube or cast iron).

  • steve617
    steve617 Member Posts: 13

    Fin tube baseboard. Sounds like a whirling sound probably from pump when boiler starts up, but gets quieter when the hot water starts circulating.

  • psb75
    psb75 Member Posts: 1,142

    Thanks. Metal sounds link "tinkling/crinkling/ticking" are heat-expansion. "Gurgling and whirling" water sounds are usually air or bubbles in the system. The bubbles/air "gather" in resting places when the water isn't moving, then they scatter and spread out when the circulator starts and make noise. Check the status of your air elimination devices and the "health" of your expansion tank. Check your system pressure on the gauge when it is running and resting. Make sure there are no leaks on the system.

  • psb75
    psb75 Member Posts: 1,142

    Corr: Metal sounds like….

  • steve617
    steve617 Member Posts: 13

    thanks

  • hot_rod
    hot_rod Member Posts: 27,509

    An oversized pump can create hissing or whirling type noise

    It could diminish as additional zones open up

    Is this a newly developed sound? Has changed in the system?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • HomerJSmith
    HomerJSmith Member Posts: 2,781
    edited April 17

    The sound changes because the velocity increases due to the heating of the water. Hot water is less viscous than cold water so it flows easier, albeit, faster with the same pressure. This is why I adjust my balancing valves at operating temperature.

  • neilc
    neilc Member Posts: 3,186

    is your circ before or after the expansion tank?

    known to beat dead horses
  • pedmec
    pedmec Member Posts: 1,374

    You sure it's related to the hot water? Do you have a Mod/con boiler? if you have a Mod/con the boiler the sound may be decreasing due to the water getting closer to the set point temperature so the ECM motor is slowing down in a effort to reduce the BTU input. You might be hearing the ECM motor slowing down. You really shouldn't be hearing water flowing thru your baseboard.

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