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touched wires together while changing thermostat

I was installing a NEST thermostat. I didn't kill the power and touched the wires together. Now that radiant zone won't work. Is the problem in the zone valve? Maybe the end switch? Or a fuse in the furnace? Thanks!


  • Harvey RamerHarvey Ramer Member Posts: 2,200
    You likely either blew the transformer or if it is in a zone panel, check the fuses.
    Ramer Mechanical
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  • sashasenkoffsashasenkoff Member Posts: 4
    Man thanks!
  • STEVEusaPASTEVEusaPA Member Posts: 3,463
    ..and turn the power off this time :)
  • Mark EathertonMark Eatherton Member Posts: 5,843
    How many wires did you have at the thermostat end? If just 2, shouldn't have blown anything. If more than 2 then yeah, you probably let the magic smoke out of something....

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • sashasenkoffsashasenkoff Member Posts: 4
    It was only 2. 1 red and I white. Where would you start? Open the furnace and look for fuses? It's radiant heat so it takes a while to heat. I put the heat up to 70 one night and it didn't go past 63. The furnace was installed in 1996. Could it burn out a zone valve as opposed to a fuse? As you can see I know very little about this kind of thing...
  • unclejohnunclejohn Member Posts: 1,420
    Most likely the nest is not set up correctly. Try tying the two wires together and see if the heat works.
  • Jamie HallJamie Hall Member Posts: 11,400
    If it's just two wires -- red and white -- and that's all you have hooked up to the Nest... it's not going to work. The red and white need to be hooked up to something which is going to close the circuit when heat is needed. Just a switch. As Unclejohn said, just try hooking those two wires -- at the thermostat -- together and seeing if you get heat.

    If I recall, a Nest -- among other idiosyncracies -- must have a dedicated C lead -- 24 volts AC always on to operate at all.

    You really have two choices -- something a less next generation and golly gee whiz, like a good programmable thermostat -- or pull a third wire for your Nest.
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • SWEISWEI Member Posts: 7,356

    If I recall, a Nest -- among other idiosyncracies -- must have a dedicated C lead -- 24 volts AC always on to operate at all.

    Like all web-enabled thermostats, it has a power budget that's just not quite workable on batteries. They claim it can power steal, but IIRC actually doing do causes it to do something ugly (reboot, perhaps?)
  • ChrisJChrisJ Member Posts: 10,226
    Isn't "shorting" the red and white together how you turn the heat on? Literally?

    The Nest claims it doesn't need a Common, but everything I've heard says it really should require one. For example, a really long call for heat can kill it's internal batteries.

    And............ I just noticed SWEI said the same thing.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • sashasenkoffsashasenkoff Member Posts: 4
    Thanks guys, I'll try to touch the wires together and see if I get heat. Thanks!!
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