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Luke_Porter's avatar
Luke_Porter
Explorer
Jul 11, 2013

Furnace problem

My furnace doesn't work, it does nothing. It does have good 12 volt power to it. Any ideas where to look?

3 Replies

  • Brand & Model would help.

    Basically 12V power goes to t-stat and also directly to furnace.
    When t-stat calls for heat.....12V is sent to timed delay relay (or circuit board) which starts fan. Fan runs and air flow makes up sail switch which allows 12V power to be sent to gas valve & Spark.

    So problem could be with t-stat, timed delay relay, sail switch, high limit switch, fan motor circuit, circuit board or tripped CB (located in outside compartment)

    Get out volt meter and start tracing power.

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