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Community and Q&A

Mitsubishi 18,000 BTU Heat Pump Boiling/Bubbling Sound?

Noll86 | Posted in GBA Pro Help on

About one year ago I purchased a Mitsubishi 18,000 btu heat pump. It is the low ambient heating version…FE series i believe not the GE. Last winter was brutally cold (northeast pa) and never had in issue. Just last night it dropped to about 7 degrees F. For the first time I noticed a bubbling/boiling sound coming from the line set and primarily the indoor unit. Like I said earlier, I had subzero temps last winter and never heard this noise. The heat pump continued to deliver warm air and my home never got chilly. I’ve always heard if ain’t broke don’t fix/worry about it. Should I be concerned with this noise? Could there be some issues with leaks/low charge? System was installed by my good friend who has been in the hvac trade for years. Any input would be great. Thanks in advance.

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  1. GBA Editor
    Martin Holladay | | #1

    I'm not sure -- but it might be time to call up your good friend who has been in the HVAC trade for years.

  2. Noll86 | | #2

    Thanks for the response Martin. I've already contacted him as well as Mitsubishi Support. He's stopping by to check the unit this evening. The women I spoke with at Mitsubishi reiterated what I have read in the book that came with the unit which is air blowing up the condensate line causing the noise. Seems peculiar that I'd never heard this before. It was windy last night but this morning it was dead calm and it still made the same sound. Thanks again.

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