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  1. #1

    Honeywell TH5220D "Auto" Setting. Confused...

    I know this probably isn't as difficult as I'm making it out to be, but I'm having a hard time understanding the Auto setting on my Honeywell TH5220D thermostat.

    When the system is on Auto, do the heat and cool temeratures tell the system when to kick on and off? I'm trying to keep my house at 67. What would I need to set the heat and cool settings at to keep it at or as close to 67 as possible? Right now I have the cool setting on 69 and the heat setting on 66. Is that what I should have it on? The manual mentions a 3 degree deadband and won't let them go any closer together than that.

    Thanks for any info.

  2. #2
    Join Date
    Jun 2001
    Location
    Louisville, KY
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    You can not maintain a constant temperature as you desire with residential equipment. There are many operational considerations that I won't get into here. Suffice to say that your equipment isn't capable of doing it.

    If you want 67F in the winter, set the heat setpoint to 67F. In the summer, set the cool setpoint to 67F.
    Perhaps you should have read the instructions before calling.

  3. #3
    Join Date
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    Quote Originally Posted by jrbenny View Post
    In the summer, set the cool setpoint to 67F.
    And expect a big cooling bill if you keep your place at 67 in the summer.
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  4. #4
    Join Date
    Jun 2001
    Location
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    Yep.
    Perhaps you should have read the instructions before calling.

  5. #5
    Join Date
    Mar 2002
    Location
    Richmond, Virginia
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    Auto setting allows the system to switch between heating and cooling without you changing the setting to 'heat' or 'cool'. Set them both at a temperature that is comfortable to you. The deadband prevents the system from frequently switching back and forth between heat and cool.
    There is nothing more frightful than ignorance in action....Mark Twain

  6. #6
    I just had a couple of TH6220s installed as part of a conversion to a hybrid system.

    According to the installation guide, which the contractor left, the "Auto" setting may disable all the other setting options--"Heat," "Cool" and "Emergency Heat"--depending upon how it's set. I also read somewhere that the "Auto" setting is intended primarily for areas with wide daily ranges in outdoor temperature (and perhaps for exceptionally lazy people??).

    To get rid of it, press and hold the "^" (up arrow) and "FAN" buttons simultaneously until the display changes. Then use the "\/" (down arrow) button until you get to function 12. Then press 0 to select manual changeover (Heat/Cool/Off) and the "DONE" button to save the setting and exit.

  7. #7
    Join Date
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    Quote Originally Posted by Mountain Man View Post
    I just had a couple of TH6220s installed as part of a conversion to a hybrid system.
    Strange thermostat to use for a dual fuel system.

    Requires a add on fossil fuel control.
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  8. #8
    Quote Originally Posted by beenthere View Post
    Strange thermostat to use for a dual fuel system.

    Requires a add on fossil fuel control.
    Why do you think it's strange? And what would you have recommended instead? The deed is done, so I'm just wondering.

  9. #9
    Join Date
    Jan 2004
    Location
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    At least a TH8320, TH8321, but would prefer the IAQ(YTH9421)

    They don't require add on fossil fuel controls.
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