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Signal lost between Argo and Aquastat Relay

rrabih
rrabih Member Posts: 38
I did just replace the Aquastat for an issue related to the joint crack. Now when there's a signal sent to Aquastat relay, it clicks and when the temp is beyond the limit (180F) it stops. this is good.

But I have one intermittent issue of the signal that is lost between Argo Control and Aquastat, let me explain:

I have two zones, with two circulators, the circulators are controlled by Argo Control box not but the Aquastat (attached image ); the Aquastat only controls the temp limit of the water (to shut the boiler).

What happens is that the signal is lost somewhere between the thermostat and the aquastat: maybe the Argo has an issue, or may be just there is an issue in cabling because the Argo control starts well the Circulators.

In summary:
- Zone-1: is for the hot water to use in the house.
- Zone-2: is for the heating; there are 3 zones valves but they all share the same zone.2 in the Argo control, if one of zone valves starts (once the temp for one thermostat in house reaches the minimum) , the signal is sent to the boiler via Aquastat.

What happens is this: the thermostat reaches the minimum temp, sends a signal to the zone valve that turns and send signal to Argo Control, which than starts the circulators and also send the signal to the Aquastat relay, if temp is less than 180F, the Aquastat sends signal to the gas valve for the boiler to starts.

the signal is lost somewhere between Argo and the Aquastat in an intermittent way: sometimes it works sometimes not....


Comments

  • Tim McElwain
    Tim McElwain Member Posts: 4,477
    What was the old aquastat numbers and what is the new?
  • rrabih
    rrabih Member Posts: 38
    OLD: E8148E 1216
    NEW: E8148E 1265

  • Jamie Hall
    Jamie Hall Member Posts: 16,607
    The most common place for a signal to go missing is at a connection. Therefore... check all the connections. If they are all good, check the wires. Then start worrying about the Argo...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • rrabih
    rrabih Member Posts: 38
    thank Jamie, will do that today, just wondering why it does it intermittently
  • lchmb
    lchmb Member Posts: 2,997
    lose wire or broken..strip all connections back and reconnect between the end switch and t-t on the aquastat.
  • rrabih
    rrabih Member Posts: 38
    thank Jamie and lchmb, will do that today, just wondering why it does it intermittently
  • HVACNUT
    HVACNUT Member Posts: 4,085
    XX terminals on the Argo to TT on the aquastat? Good connections?
    XX closes on a heat demand and tells the boiler to fire as long as it's below limit.
  • Jamie Hall
    Jamie Hall Member Posts: 16,607
    rrabih said:

    thank Jamie and lchmb, will do that today, just wondering why it does it intermittently

    That is exactly the nature of a bad connection...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • rrabih
    rrabih Member Posts: 38
    didn't check it yet as it was really working all day long yesterday, but stopped again around 4AM in the morning.
    I checked TV-W: it is 24V; but T - W is noting;
    I did turn off all and turn on again and it clicked; checked T-W it was 24V this time.
    will check all connection this weekend, but I still have a doubt, this behaves as if there's a fuse somewhere that blows sometime!

  • Jamie Hall
    Jamie Hall Member Posts: 16,607
    Ah... unless it is a self-resetting circuit breaker or thermal overload, it's not a fuse or circuit breaker. You have to reset those yourself. And if it is a self-resetting circuit breaker or thermal overload, then you do have a problem -- and best you should find it.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • rrabih
    rrabih Member Posts: 38
    Thanks Jamie: there's no circuit breaker at this level, no thermal overload;

    I have checked all wiring and no issue to mention. the strange thing is:
    - it usually works when the cycle between two calls for heat is long: for almost a week, the cold was soft, the thermostat calls for heat with long intervals, the signal passes through to aquastat without a problem; it never stops for more than 5 days. This is probably because there was enough time for everything to cool down before the next call of heat.

    - This last two days, the temp went down below 25 degrees again, and the cycle becomes short between two calls of heat and again the signal seems to be lost.

    I Normally turn off/on all to it to work when it stops, but I did try today to just use a jumper between TTs (of aquastat) and once it kicked, I did remove the jumper and it keeps working...this is really strange!

    any explanation?
  • Jamie Hall
    Jamie Hall Member Posts: 16,607
    Almost sounds as though the aquastat may be sticking open for some reason.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • rrabih
    rrabih Member Posts: 38
    edited January 2018
    the aquastat is new just installed as I though this was the issue, but seemingly not...
  • Jamie Hall
    Jamie Hall Member Posts: 16,607
    Thing is, if it ran when you shorted across the aquastat -- which is only a switch -- and hadn't before, the problem pretty well has to be either the aquastat switch wasn't closed -- or could there be a problem with the wire connections right there?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • rrabih
    rrabih Member Posts: 38
    Hi All,
    just to let you know that replacing the Argo fixed the issue. There should be just a problem with the relay, but replacing the all thing is better.
    thank you all for your help..