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Smoking....

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STEVEusaPA
STEVEusaPA Member Posts: 6,505
Yeah you're getting a new aquastat, and were changing out all the old control wiring that has the cloth insulation...


There was an error rendering this rich post.

TinmanSuperTech

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  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
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    Once you let the smoke out.....
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
    kcopp
  • mattmia2
    mattmia2 Member Posts: 9,959
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    Does that have something to do with something shorting or is that because the terminal wasn't soldered right or someone torqued on it enough to loosen the solder joint or just didn't tighten the screw?
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    edited February 2020
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    Looks like it shorted. No field soldering on those controls. Doubt it was torque, as no one probably touched those wires since in was installed in the late 80's.
    To me I think it was the wiring itself. Older wire that has cloth-like insulation inside the MC, falling apart inside the control. No black marks on L2 (also no ground).
    All wiring replaced now. I posted a picture before of the whole mess, circulators with zone valves as check valves, and contactors/relays galore...

    There was an error rendering this rich post.

  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
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    I love zone valves as flo-checks! Double the fun!
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • mattmia2
    mattmia2 Member Posts: 9,959
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    I meant the terminal where it was soldered to the board at the factory, it is common n all sorts of other PCBs, especially where it is high current although those usually show up more in the 10 yearish range (or the pads on the board weren't big enough and it just failed over time).

    Another thought i had was that a wire was folded against the terminal and chaffed after decades of vibration.

    Since I don't see a clean area where the wire was contacting the terminal under the screw, my biggest suspect is the screw wasn't tight enough and over decades of heating and cooling and vibration it loosened up and burned up.
  • nibs
    nibs Member Posts: 516
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    Why not whip out yer soldering iron and do a field repair?
  • unclejohn
    unclejohn Member Posts: 1,833
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    I always said that it doesn't matter how good a service tech. you are a part will fail.
  • HVACNUT
    HVACNUT Member Posts: 5,888
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    > @nibs said:
    > Why not whip out yer soldering iron and do a field repair?

    Because you don't do a heart transplant on a 100 year old with stage 4 bone cancer.
    SuperTechBrewbeer
  • SuperTech
    SuperTech Member Posts: 2,205
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    I had a triple aquastat burn up like that once. They smell terrible. Never figured out why it happened. Installed a L7224U and the boiler was good to go.