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Steam boiler not starting

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I have an issue with my One pipe steam boiler that will need your expertise. Nest will call for heat and dial turns orange, but the boiler will not fire. The green light on the boiler is on but it will not fire. I will have to manually use the boiler power wall switch to turn it off then back on then it will fire. This happens some days first thing in the morning. I don’t have a setback.

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  • B_Sloane
    B_Sloane Member Posts: 56
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    FF lock out
  • neurosteam
    neurosteam Member Posts: 34
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    I apologize. What is FF LOCK OUT.
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
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    Oil/gas? Does nest have a common wire connected?

    There was an error rendering this rich post.

  • Steamhead
    Steamhead Member Posts: 16,885
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    @neurosteam , where are you located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • neurosteam
    neurosteam Member Posts: 34
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    Gas. Nest has no C wire. Battery voltage at 3.82.
    Located in Buffalo NY. No steam experts around
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    edited February 2020
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    Use a jumper wire on the terminals of the nest to mimic a call for heat, and see if the boiler fires, and repeat several times.
    If it fires reliably that way, replace the nest with a round (t87?) Honeywell thermostat, set for steam.
    Return the nest, or hang it on the Christmas tree, later this year. Do a search for all the posts here about nest problems, and you will see how badly they handle any sort of non-forced air heating system.—NBC
    STEVEusaPA
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    edited February 2020
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    Or add the C wire. There are a few ways depending on what controls you have at the boiler, or if adding a transformer, or for oil a Kool-Kit, as shown by @Robert O'Brien in a published article (that I can't seem to find in my archives).

    There was an error rendering this rich post.

    neurosteam
  • neurosteam
    neurosteam Member Posts: 34
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    Thank you Nicholas
    Thank you Steve
    Very helpful. I will replace the nest for sure, one more ornament for the Christmas tree. 😂