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Honeywell digital thermostat won't turn off ac.

I justmoved in to this house and I have a honeywell digital thermostat. I can't seem to get the thermostat to turn off the ac. Even in the off position for the switch the air is still on. What can I try? I have read that you need to have the temp. set at least 6 ot 7 degrees higher so that it will turn off but I have tried that and it didn't work. I'm getting cold! Need advice.

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The Honeywell CT87 thermostat is a normal round thermostat, not digital and may have a sub-base installed with it that has a two switches on it. One is for Fan (Auto or On)and the other is for Heat, Cool and Off. Make sure the Fan switch is in the Auto position and the other switch is in either the Cool or Off mode. If you continue to get cooling, you have a short in the thermostat wire or a stuck relay in th indoor or outdoor unit. To test this, while the unit is running; remove the round outer ring on the thermostat by pulling it straight off towards you. You will find 3 slotted head screws that hold the thermostat to the sub-base. These screws are located at the 3 o'clock, 7 o'clock and 9 o'clock positions. Turn these screws counterclockwise with a small head screwdriver. They are held in place so should not fall and get lost. With the front of the thermostat removed from the base, the air conditioner should stop running. If the unit continues to run, you will need to have your A/C system inspected by a technician. If in fact your thermostat is digital, look to see how it is mounted to its sub-base and remove it. If the system stops, you may have a bad thermostat or the Fan switch is in the On position. Hopefully this will help.

Posted on Sep 12, 2007

  • Chandler Ede
    Chandler Ede Sep 27, 2007

    What did you discover? You gave me a poor rating without a solution, what gives?



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