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Laars Minitherm clicking noise

stuyguy
stuyguy Member Posts: 21
A Laars Minitherm hydronic boiler (75K BTU Model JVT075NDJS) was installed in April 2011 to heat the 2nd floor of my mother's house. It began to make a loud clicking noise yesterday, but does so intermittently. The noise coincides with the low water cutoff light alternating between red and green. The noise seems to happen when the boiler wants to fire. Cycling power to the unit seems to eliminate the problem for a while but it then reoccurs. I live 2000 miles away and don't have this type of heating system. Any idea what's causing the noise?

Comments

  • kcopp
    kcopp Member Posts: 4,393
    you got a problem....

    sounds like the boiler water needs to be filled and purged. W/ that boiler the heat exchanger is copper and needs a lot of flow. If there is not enough water OR the circulator is not moving water fast enough the copper fire tube could be compromised.
  • stuyguy
    stuyguy Member Posts: 21
    Thanks for the reply

    Two months ago, the system was filled/purged due to other noise issues in the pipes. Does this type of system need to be filled/purged every few months?
  • kcopp
    kcopp Member Posts: 4,393
    it shouldn't...

    It should  be fine after 2 month. Does it have a "fast fill" on it? Watts 1156 or a 911s are examples.
  • ColoradoDave
    ColoradoDave Member Posts: 54
    Air elimination

    It could also be a problem with your air elimation.  If the air can't get out, it WILL gather together.  If enough gathers together, your pump is pumping down, the air gets into the pump and if enough of it is there (or rather, not enough water for the pump to move) then it's cavitated and the flow through the boiler slows down enough it starts popping (it's water flashing to steam).  When you turn the system off, the air rises and the pumps full of water again... you turn it on and the air gets broken up into smaller gulps of air and the problem goes away until the air manages to gather again.

    Check your air vents to make sure they're working right.
  • stuyguy
    stuyguy Member Posts: 21
    edited December 2011
    Fast fill

    It has an Apollo fast fill regulator, model FF. The PSI when the unit isn't running is 20; reaches about 30 when it's running
  • stuyguy
    stuyguy Member Posts: 21
    Air vents?

    There aren't any on the 2nd floor. Argo baseboards run along the perimeter walls. No vents I can see upstairs. Don't see any around the unit either
  • kcopp
    kcopp Member Posts: 4,393
    No air scoop?

    Got to have a way for the air to get out. Also the extrol tank could be bad. Pictures are out of the question? You are not near the job? Maybe its time to call in a pro? Where is thee boiler?
  • stuyguy
    stuyguy Member Posts: 21
    edited December 2011
    Thanks for the reply

    The initial symptoms (LWCO preventing boiler from firing) haven't reappeared since Tuesday night. Today a plumber (1) set temp on heater to 175; it had been set to 130; (2) set aquastat to 210; it had been set to 240+; (3) replaced expansion tank with a larger model (4.8 gallons); old tank was full of blackish water. Boiler is in the basement. System is heating the 2nd floor faster now. There are minor gurgling sounds. Is this system supposed to be completely quiet? Also, is the LWCO correctly mounted on the return side?



    If you see an air scoop in the pictures, please let me know where it is
  • kcopp
    kcopp Member Posts: 4,393
    edited December 2011
    Lot of stuff to work ....

    on.  1. Missing air scoop/ air seperator. 2. Boiler is just plain piped wrong.... you can't pipe them in 3/4"! and it needs a bypass. Flow is everything on that HX.  3. Should be piped pumping away from the extrol tank. 4. no drip tee on the gas. 5. That is a terrible way to have that exrol tank. If/ when it water logs it could bend that copper tubing...Was this installed by a professional? What state/ town is this in?
  • stuyguy
    stuyguy Member Posts: 21
    Thanks for the feedback

    Installed by a licensed plumber hired by general contractor for remodel of 2nd floor in Astoria, NY. I'm having someone else come have a look soon. I'll pass on your observations
  • Steve_210
    Steve_210 Member Posts: 645
    edited December 2011
    One thing

    I don,t think you are allowed a drip leg on the gas anymore in NYC ( code)
  • kcopp
    kcopp Member Posts: 4,393
    Really...

    why? what harm would be done by having one? If anything it protects the gas valve....
  • stuyguy
    stuyguy Member Posts: 21
    A pro took a look

    He will add an air scoop and a bypass and reconfigure the piping so that the expansion tank is properly located. He says NYC no longer wants drip legs. I found him using this site's "Find a contractor" feature, and it's worked out well for me. Thanks to everyone for their input
  • stuyguy
    stuyguy Member Posts: 21
    Here's the after

    A Superior plumber made it right
This discussion has been closed.