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Troubleshooting help needed! LG mini-split leaking from air outlet

I installed an LG mini-split, 4-zone less than 1 month ago, and one of the zones is dripping water from the air outlet.

I have poured water over the evaporator and it drains fine. There does not appear to be icing of the evap. Air filter is clean. Any other ideas?

The unit installed is a
LSN120HSV5 IDU - leaking unit
LMN079HVT IDU - (x3)


  • ratio
    ratio Member Posts: 2,726
    High humidity in the space with the dripping head? It's my understanding that mini split heads don't shut off refrigerant flow completely due to oil control issues, so that head may be getting overcooled in the wrong places & condensing in places it shouldn't. Also check the heat gain vs head size. Does it satisfy? Is the temp set to something unreasonable?
  • motoguy128
    motoguy128 Member Posts: 335
    edited August 2020
    We only sell Fujitsu, but I’ve never seen this. Only leaking has been kinked, plugged or inadequate Drain pitch on a long lineset. But you said it drain fine when water poured on it.

    Is it in a room that’s really humid? Wall sealed behind the unit? I wonder if humid air is condensing on the louvers. Same thing happened to conventional system with ceiling registers below hot/humid attics. The metal is 50F and humid air drawn across the ceiling will condense on it.

    Actually I believe most dust accumulation on wall mount minisplit blower wheels is actually form dust in the room, not return air.

    So if hot humid air is in the room at the ceiling, it may be condensing on the 45-50F plastic louvers or just inside the fan blower shroud.
  • bio_guy
    bio_guy Member Posts: 69
    When this happens with ducted systems that cycle, bang bang, on and off, is the condensing happening when the blower is running or off? If the latter, it does not really apply to mini splits that have the blower wheel turning all the time, does it?

    If the unit is cycling rather than just throttling back, the coil could be warming up above the dew point faster than the downstream plastic bits. If that is happening, the cold plastic bits could be getting hit with air that is very saturated since the blower does not stop completely.

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