The Wall
Forum / Controls / troubleshoot aquastat no circ
  • Post a Reply to this Thread

    troubleshoot aquastat no circ (13 Posts)

  • vp007 vp007 @ 12:30 PM
    Contact this user

    troubleshoot aquastat no circ

    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.
  • Zman Zman @ 6:07 PM
    Contact this user


    If you jumper the TT terminals on the 8124, what happens?
  • vp007 vp007 @ 6:31 PM
    Contact this user


    jumper and nothing
  • Zman Zman @ 6:51 PM
    Contact this user


    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.
  • vp007 vp007 @ 7:48 PM
    Contact this user


    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 @ 6:54 PM
    Contact this user


    The pushing on the board problem reads like a bad board of maybe a loose neutral somewhere. Double check the neutral wires.
  • vp007 vp007 @ 7:35 PM
    Contact this user


    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.
  • Zman Zman @ 7:54 PM
    Contact this user


    Sure sounds like the board.
    Double check all connections
  • vp007 vp007 @ 7:59 PM
    Contact this user


    thanks gents - should have one in my hands tomorrow
  • vp007 vp007 @ 9:18 PM
    Contact this user

    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 @ 9:03 AM
    Contact this user

    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.
  • vp007 vp007 @ 10:10 AM
    Contact this user


    that was what i needed. that last line was the answer. still helpful for me fine tuning the settings. thanks
  • SWEI SWEI @ 9:57 AM
    Contact this user
Post a Reply to this Thread