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My Home Ac Is Set On Auto And At 75 Degrees. This Morning It Was 69 Inside. Why Is Auto Not Shutting Off?
Categories: Q & A

7 Comments to “My Home Ac Is Set On Auto And At 75 Degrees. This Morning It Was 69 Inside. Why Is Auto Not Shutting Off?”

  1. Amber B says:

    Ok, first of all the ‘auto’ and ‘on’ have nothing to do with cooling or heating that setting just controls how your fan operates. In ‘auto’ the fan cycles on and off with the heating or cooling. In ‘on’ the fan runs continuously regardless of whether the heating or cooling is on. If your cooling is running and the thermostat is set well above what the temperature is at the thermostat you either have a bad thermostat or a shorted control wire.

  2. B-Notabl says:

    The easiest way to check if the thermostat is defective is to remove it from its base. Most digital thermostats will unsnap from the base with a little bit of gentle prying at the top or bottom. If you have a mercury type thermostat then the thermostat will probably be held onto the base with a couple of screws. Remove the front cover and take out the screws. By removing the thermostat, you are removing the complete control circuit to the air conditioner. If the A/C shuts off, then your problem is a defective thermostat. If the A/C continues to run, then you have a problem in your wiring or the circuit board in your furnace. If the inside fan shuts off and the outdoor unit is still running, then you most likely have a welded contactor. Shut the unit off at the disconnect outside and call an HVAC service company. Good luck.

  3. Papa C says:

    It depends on where your thermostat is. Mine was upstairs and as heat rises the thermostat didn’t turn off until it was 75 upstairs but it was much cooler downstairs. Is the sun hitting the thermostat? Is the thermostat set on continuous instead of automatic? I also found out that my thermostate was wired wrong. When I had it on automatic it was continous!

  4. virginia says:

    try to set the thermostat slightly higher while the fan is running, you will hear the compressor stop, this is the indication, hopefully the temperature you require.
    Good luck

  5. GT says:

    sounds like you need a new thermostat. is the thermostat you have now a mercury thermostat? If it is replace it with a digital one. I pretty sure the thermostat is the problem

  6. BRYAN & SHANNON R says:

    if temp 69 it should shut off, some time thermostat can go bad, cheapest way buy a new one do it yourself cost about $ 30 – 50,
    if you call A/C tech to replace it for you they will charge at least $ 150
    good luck

  7. ppe says:

    Maybe an issue with your thermostat

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