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honeywell 8000

has anyone had this experience; when the batteries die, the system stays in it's last call, heating or cooling?


  • adambuild
    adambuild Member Posts: 413

    As far as I recall, the stat dies and acts as if there's no stat at all until the batts are changed.
  • it was my understanding

    that the batts were only used to keep the progams alive if the 24v source failed. but i heard from a colleague that he noticed, on two occasions, that the unit stayed in whatever mode it was in when the batts died; ie, if it was during transitional weather, the unit stayed in cooling when it was cold enough for it to be called on for heat

  • Bill W@Honeywell
    Bill W@Honeywell Member Posts: 164

    There are two ways of powering a VisionPro(8000) series stat. One is with batteries, and the other is by hard wiring it into the system. The batteries power the thermostat when it is NOT hard wired. The "batt lo" message flashes for 30 days before the batteries die. Once you replace the expired batteries, you will need to reset the clock and the date, but the rest of the program will still be there. If the stat is hardwired, the batteries serve as a backup if the power goes off. For more info, go to www.customer.honeywell.com, scroll down to the lower right, type in the stat part number, and you will get a PDF file of the technical sheets for this product, showing wiring diagrams and other tech data. It's free, and no password is necessary.
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