Question about Honeywell Programmable Thermostat Heater

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Fan runs indefinitely after heat shuts off

Last month we had a power outage that fried our thermostat and one of our breakers, so we replaced both. The heater works now, except the fan continues to run forever after the heat turns off therefore blowing cold air. The honeywell tech people say I have everything wired correctly, so I really don't know what to check now. We've been using the emergency heat since that seems to work just fine, but were in for a shock when we got our electric bill. Can anyone point me in the right direction?

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  • Chellynae Jan 05, 2009

    The thermostat is RTH3100C, which is a Honeywell Non-programmable Digital Thermostat. I believe our system is a Trane. Thanks so much for looking and giving any advice you might have.

  • Chellynae Jan 05, 2009

    No the fan does not run constantly when it is set to E-heat. It just runs while heat is on and shuts off when it is supposed to.

  • Chellynae Jan 05, 2009

    For the thermostat, yes. I have the installation guide.

    The entire system came with the house though, so I don't have any info on that. It is only a few years old though.

  • Chellynae Jan 05, 2009

    Ok. Checked the settings according to the guide, and all is correct.

  • Chellynae Jan 05, 2009

    Yes. Although, it's not consistent. Some days the stupid thing never shuts off, and others it seems to work fine.

  • Chellynae Jan 06, 2009

    Hmmm, I never thought of that since it is brand new, but that's entirely possible. Thank you so much for your help! I will replace it and see if that takes care of the problem. Thanks again!

  • Chellynae Jan 06, 2009

    Would love it if you would post this as a solution so that I can rate you as very helpful dwkcool!

  • Chellynae Jan 06, 2009

    The heater worked just fine yesterday on regular heat, but this morning when I woke up it was chilly and is blowing cool air again. So, it seems like maybe the problem only occurs after it has been on for a while. Do you still think that could be thermostat, or do you think something is actually wrong with the heating element or something else?

  • Chellynae Jan 06, 2009

    I don't think so. The E has a black wire in it and the Aux has the white wire. Do I need a jumper?

  • Chellynae Jan 06, 2009

    Well, that makes absolute sense since it only seems to happen after it's been running for a while. I will put in a jumper tonight and see if that helps. I have a feeling that it will! I'm in Texas though and the weather has already swung to warm, so I will have to wait for the next cold front to know if it worked for sure. Thank you so much for your time and expertise! You have no idea what a blessing it is!

  • dwkcool May 11, 2010

    sounds like you might have a bad t-stat

  • dwkcool May 11, 2010

    has the problem been the same since you put the t-stat in

  • dwkcool May 11, 2010

    check your set guide for the t-stat on the setup program

  • dwkcool May 11, 2010

    do you still have your setup papers

  • dwkcool May 11, 2010

    the fan does not run forever on E-heat

  • dwkcool May 11, 2010

    what style honeywell is it and what brand system do you have



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Yes I have replaced a couple of t-stats lately (honeywell)

Posted on Jan 06, 2009

  • dwkcool Jan 06, 2009

    did you put a jumper wire in from E to AUX where your white wire connects

  • dwkcool Jan 06, 2009

    yes so when it goes into defrost it will have enough backup heat to keep up with the house



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