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Amtrol keeps trying to fire but won't fire the furnace

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pfunk
pfunk Member Posts: 9
in THE MAIN WALL
I have an Amtrol WH-7L and I’m having some issues with it. What happened was the aquastat relay on my QB-180 Weil Mcclain boiler would click on then release. I changed the aquastat relay, no change, changed the eye, no change, changed the primary controller and no change. What we found was that the furnace would kick on when the thermostats in the house called for heat but the water heater wouldn’t fire the furnace. We noticed that the green light on the front of the water heater would blink and it looks like the power on the front of the unit goes out for a second and then comes back on. Any ideas?

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  • HVACNUT
    HVACNUT Member Posts: 5,835
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    Thats a lot of parts. Kind of like throwing darts while blindfolded.
    An electrical meter would really help.
    What model Amtrol control?
    Besides the Amtrol Smart Control possibly being faulty, it could be the wiring between the control and relay or zone valve, or the relay or zone valve itself.

    Can you post pics of all? Controller, aquastat, relays, etc. Not too close.
  • Jamie Hall
    Jamie Hall Member Posts: 23,286
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    Always check all your wiring and connections before you start throwing parts at it...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • pfunk
    pfunk Member Posts: 9
    edited December 2019
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    I went down this morning and flipped the service switch to on and it fired right up but it’s done that in the past where I would leave it off and then switch it back on and it would fire over, but that was switching off the boiler not the water heater
  • pfunk
    pfunk Member Posts: 9
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    And the wiring from the Amtrol goes to the aqua stat relay
  • HVACNUT
    HVACNUT Member Posts: 5,835
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    Why are there 2 sets of low volt wires to TT on the aquastat?
    What is providing constant 24v to the Amtrol control?
  • Zman
    Zman Member Posts: 7,569
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    Is the domestic circulator turning on but not the boiler?
    What is controlling the circulator? A picture of that would help.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • pfunk
    pfunk Member Posts: 9
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    The two low volt wires going to the aquastat relay are from the water heater, and another coming from the control for the baseboard heat. The circulator for the hot water heater is in the water heater and that turns on when the control in the water heater tells it to. when the hot water heater needs it, it sends the signal over to the boiler to tell it to turn on and as long as it is not at it's high limit, it should fire.
  • pfunk
    pfunk Member Posts: 9
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    this is the controller on the front of the water heater
  • Zman
    Zman Member Posts: 7,569
    edited December 2019
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    It looks like the amtrol control should be turning on the circ and telling the boiler to fire. Is it turning on the circ? If you jump the TT wires to the boiler, does it fire? You may have a bad controller on the Amtrol.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • pfunk
    pfunk Member Posts: 9
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    That circulator works fine, I can hear it running no problem when the water heater wants it to run. You can even see the green light on the control showing it’s running but the only problem is when the water heater calls the furnace for heat the relay in the aqua stat will pull in for a second and then click right back off without the furnace firing but when it does do that, the lights on the water heater controller flicker
  • Zman
    Zman Member Posts: 7,569
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    I am thinking that something in the Amtrol controller is bad. Do you have a voltage meter?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • HVACNUT
    HVACNUT Member Posts: 5,835
    edited December 2019
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    Whatever the problem is, there shouldn't be 2 sets of low volt wires to TT on the aquastat.

    Again, how is it that the smart control has constant 24v?
    The answer is, I dont think it does. It's getting a false 24v through the aquastat transformer coil, then on a domestic hot water demand it loses it for TT's purpose of switching only.
    You cant use the aquastats transformer for power.
  • pfunk
    pfunk Member Posts: 9
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    I’m not totally sure how this thing works but it’s been like this for over ten years and all of a sudden it’s not working. I’m going to open the hot water heater and see if I can figure it out because I think the hot water heater controller is bad
  • rick in Alaska
    rick in Alaska Member Posts: 1,457
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    The "smart control" on those are notoriously bad. I have a shelf full of bad ones from all the revisions they have done. My money is on a bad control. If you only need it to power the tt on the boiler, you can get the old style mechanical control to put on there. They are much more reliable. If however it is also powering a pump, then you should stick with that control.
    Rick
  • pfunk
    pfunk Member Posts: 9
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    Rick, I think you are spot on, bad control. I picked one up for 240 delivered so once that comes I’ll switch out. It’s pretty old, so in this boondoggle I’ve got a new aqua stat relay new eye new primary controller and now a new controller on my water heater and with all that I have a spare eye and primary controller if I ever need them. It was a learning experience for me as I have never worked on a furnace and I get an u we hard question right out of the gate. Thanks everyone for your input and I’ll let you know if I’m still having issues after the swap
  • Zman
    Zman Member Posts: 7,569
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    I would suggest buying one of these https://www.fluke.com/en-us/product/electrical-testing/basic-testers/fluke-t5-600
    and one of these https://heatinghelp.com/store/detail/quick-and-basic-hydronic-controls-a-contractors-easy-guide-to-hydronic-controls-wiring-and-wiring-diagrams-practice-is-good-p-i-g-technical-training-series

    It would have paid for itself on this project alone :)
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    HVACNUT
  • pfunk
    pfunk Member Posts: 9
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    I changed out the control and that fixed the problem. The controller was having problems previously in the fact that I had it set for 128 and when the furnace wasn't running to heat the house, it worked fine but when the furnace was running for house heat, the water heater would damn near scald you....so I'm hoping this fixes that problem as well. The control was 240 and I think the new aquastat was 125 and i needed both of those because the aquastat was definitely going bad according to numerous people because of the constant hum coming out of it. but I also now have an updated controller and a spare in case this one goes bad. I'm guessing that if I had to call somebody I would have probably been double this and no spare parts so not to terrible. Thanks again everyone
    rick in AlaskaZman

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