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troubleshoot aquastat no circ

vp007
vp007 Member Posts: 7
in Thermostats and Controls
Trying to see why my aquastat 8124 is not turning on circulator. Aquastat was just replaced 2 years ago because of the relay. I don't see any burns on it anywhere. Solder is solid throughout. Checking for 24v at the thermostat terminals of the controller and i get nothing. Thought the head valves were bad, but I tested the switches on both and they seem fine. 24 runs through 2 thermostats to valves and properly opens them. Noticed if I pushed on system board with volt meter leads, I get 24v and the circ comes on. Really sounds like board, but I'm not convinced. Why don't I get 24v at the terminals unless the relay fires? Ran 24v directly to thermostat terminals on AS and still nothing.

Comments

  • Zman
    Zman Member Posts: 7,611
    TT

    If you jumper the TT terminals on the 8124, what happens?

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • vp007
    vp007 Member Posts: 7
    jumper

    jumper and nothing
  • Zman
    Zman Member Posts: 7,611
    Voltage

    Does it make a noise when you jumper? Is there voltage across TT?

    I would you voltage going in to be sure you have 120+/-

    Then check the other side of the transformer for 24.

    I would guess a smoked transformer.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Zman
    Zman Member Posts: 7,611
    Neutral

    The pushing on the board problem reads like a bad board of maybe a loose neutral somewhere. Double check the neutral wires.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • vp007
    vp007 Member Posts: 7
    combo

    The panel has 120 and 24 are going to the valves. Controller is running the burner and hot water properly. Relay kicks, then the burner fires. No power at the c1 + c2 unless I push the board, then I get action & 120v to the taco.



    The thing I don't understand is how I don't see 24v at the panel or on the wires coming in from the valves. Thermostats & head valves work properly, but then the red wires that feed the TT contacts have no juice. If i check continuity on the valves, both yellow and both red wires have continuity when the switch triggers. That's supposed to send the call for heat. Sound right?



    I'm just baffled that this panel seems to have gone bad so quickly and suddenly. Yesterday morning the burner motor kept throwing its thermal switch. I replaced it and it has been fine for 36 hours.
  • vp007
    vp007 Member Posts: 7
    jumps

    There is no noise - no anything when I jumper without any signal from the thermostat.

    Transformer is sending wires to thermostats and through so the valves open. I get 24v into the valves (naturally if they are working.)
  • Zman
    Zman Member Posts: 7,611
    Board

    Sure sounds like the board.

    Double check all connections

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • vp007
    vp007 Member Posts: 7
    board

    thanks gents - should have one in my hands tomorrow
  • vp007
    vp007 Member Posts: 7
    and the answer is

    gentlemen, I have finally figured this out unfortunately another $264 lighter. the circulator will not trip until the low temperature has been reached. i appreciate your assistance. i have spare parts for next time :)
  • Zman
    Zman Member Posts: 7,611
    Which 8124?

    I am curious as to which aquastat it is. Is there another aquastat wired in somewhere?

    The circulator closing on low temp is odd, it is supposed to carry heat away from a hot boiler.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • SWEI
    SWEI Member Posts: 7,356
    Handy reference

    http://firedragonent.com/triple.pdf
  • vp007
    vp007 Member Posts: 7
    brilliant

    that was what i needed. that last line was the answer. still helpful for me fine tuning the settings. thanks
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