GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Audio Play Icon Headphones Icon Plus Icon Minus Icon Check Icon Print Icon Picture icon Single Arrow Icon Double Arrow Icon Hamburger Icon TV Icon Close Icon Sorted Hamburger/Search Icon

Community and Q&A

Mitsubishi minisplit popping noise during heating

tjolson | Posted in General Questions on


My mini-splits are already getting a workout heating our home in Vermont. There is a unit on the main floor and a second upstairs near our bedroom – each unit is fully independent. The upstairs unit is constantly popping during use to the point that it wakes me up multiple times a night. Has anyone experienced this before? Any suggestions? Everything is still under warranty and I’m calling the installer but am curious if this is a common issue?

Thanks. The model number is: MSZ-FH15NA.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Nathan Scaglione | | #1

    You are probably hearing the defrost mode - the outside coil accumulates ice which must be melted off. The refrigerant reverses direction, which makes a sort of rushing/popping noise. The colder and icier it gets the more frequently it runs. When the weather is bad enough every 15-20 minutes is possible. Nothing to do about it. You could see if the downstairs unit can heat the whole house and turn the bedroom off at night.

    1. User avatar
      vap0rtranz | | #3

      Yup, have a Bryant system (re-branded Medea) and it makes the same popping / rushing sounds. All these units have so many plastic pieces in the housing that my guess is the plastic really can't rapidly expand/contract ... but I'm no expert.

      How new is your system? Because after 3+ months, the popping sound started to be quieter, so perhaps there's a break-in period.

  2. User avatar
    Walter Ahlgrim | | #2

    The sound I hear in the file is mechanical. My wild guess is something is is restricting the motors that move around the vanes that direct the airflow. Only a wild guess.


Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |