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Chirping Sound From Indoor Minisplit

GreyWolf92 | Posted in General Questions on

My power went out 4 days ago while running my AC. Since then, the unit makes a chirping noise that almost sounds like a bird (It is not a bird or animal..I looked very closely). 

It’s making this noise on and off and sometimes goes away. Even when I turn the breaker off, the noise is still there. 

Sometimes I will turn the AC on to get rid of noise, and then it randomly comes back. Someone online thought it could be the refrigerant turning from liquid to gas.  What do you think?

I attached a video. Please turn the volume up.

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  1. Expert Member
    Akos | | #1

    Is that a multi split or a single unit? Sometimes the multi split will dump refrigerant through the non operating head when the other head cycles off.

    1. GreyWolf92 | | #2

      Thank you for the reply. It's a single unit. Everything seems to be working fine (ac and heat). Should I be worried about refrigerant leaking?

      1. Expert Member
        Akos | | #3

        The noise can be either
        -mechanical, some blower or motor is running when it shouldn't
        -refrigerant flashing off in the indoor head
        -electrical, one of the power supplies or inverter is not well designed or semi-smited (some outdoor units make a similar noise when they are not running).

        If you click off the breaker and it is still making that noise that it can be only refrigerant. Most units do have a bit of a whoosh sound when you power them off but not for very long.

        It could be that it was always there you just started playing more attention to it. For example, one of my wall mounts has a blower with a bad bearing. I never noticed it before but now that I know what the sound is, I can't not hear it.

        1. GreyWolf92 | | #4

          Thank you for the advice.

          Ok so to be clear... because it still makes the noise when the breaker is off, you say it's 100% the refrigerant? Does that mean it's leaking? If so, should I be concerned for my health?

          And what does it mean exactly "refrigerant flashing off in the indoor head"?

          What would you recommend the next steps for me?

        2. GreyWolf92 | | #8

          Is there any chance of a leak with the AC working completely fine?

  2. walta100 | | #5

    I doubt the sound is refrigerant escaping the system IE a leak.

    Flashing off is when the liquid refrigerant boils and turns gas and sound like boiling water in a pan.

    Without any valves or restriction in the indoor refrigeration tubing you could hear sounds like boiling water or flowing water. I cannot think of a way to get the chirping from the refrigerant.

    I know you said it is not electrical but it sounds likes a motor to my ear. There are small motor in most minis to move the air vanes left and right deluxe models have 2 and move up and down also. Are there any wires that go from the indoor unit to the outdoor unit?


    1. GreyWolf92 | | #6

      Hi Walta,

      Ahh thanks for clarifying. Others have said the sound could be turning from liquid to gas as well. I think that makes the most sense. Is there anything that would make this randomly starting doing this? It happened after a power outage.

      Yes there are wires that go from indoor to outdoor unit. This is the only unit in the house.

    2. GreyWolf92 | | #7

      Is there any chance of a leak with the AC working completely fine?

  3. sixis | | #9

    did you solve the problem?
    mine does exactly the same. Chirps when its off. when its cooling the sound is gone.

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