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Hydronic system noise

Bill57 Member Posts: 1
My Laars EBP 110 gas boiler and hot water radiation system is making loud noises shortly after unit fires up, and the sound often continues for a minute or two before abating or unit approaches shut off temperature. The pressure stays 16-17 PSI at all times. I've isolated the external circulator and it seems ok. As the unit is a combination space and DHW, I also isolated the internal pump and that seems also to be operating quietly. The inducer fan has just been replaced and was not the cause of the noise. The expansion tank seems ok.  All slant fin baseboard radiators are providing heat with no gurgling or banging noises, and the DHW on demand is operating well. The noise is baffling me; it began this Fall and has gradually increased in intensity and duration. I cannot seem to isolate where the noise is coming from; the external piping may be acting as a sound speaker, but I have noticed the sound seems louder in the zone being heated. Any thoughts/suggestions ???


  • Lance
    Lance Member Posts: 270

    I am not familiar with this product, but it sounds like a combustion problem. You may be out of adjustment, or a leak is in the burner area, or the burner has deteriorated.

    To eliminate this as a cause, try shutting off the gas valve while running & making the noise to see if you get a quick response. If silenced immediately look at a burner combustion problem. Combustion testing may be in order.

    Gas pressure regulator?

    Is your pressure gauge validated? Will it go to zero if you drain pressure off?

    Hope this helps.
  • Bill H.
    Bill H. Member Posts: 30
    hydronic system noise


              Thanks for your input. My pressure gauge drops to zero after draining off about a quart. I had the gas company readjust the combustion which has helped but hasn't totally eliminated the noise. They talked with a factory rep and now think the anti-condensing valve may be the culprit. As they didn't think it necessary to replace it immediately, I'll wait until milder less snowy weather as some draining to outside will be req'd. I'll update as things progress.
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