HVAC Code Lookup

LG Mini-Split Code CH35

Soft lockoutShown as: Outdoor LED01 (red) blinks 3 times, LED02 (green) blinks 5 times

Low pressure error - suction pressure has dropped below the recommended limit. Usually low refrigerant charge, a restriction, or badly blocked indoor airflow.

Manual wording: “Low Pressure Error; Pressure dropped below recommended limits”

Documented for: All LG residential mini-split outdoor units fitted with pressure sensors

Likely causes, most common first

  1. Overload operation - outdoor fan restricted, screened, or blocked
  2. Refrigerant leakage (insufficient charge)
  3. Bad connection of the pressure sensor
  4. Bad compressor sensor
  5. Bad PCB

What you can safely check yourself

  • Check and clean the indoor air filters
  • Make sure the indoor supply and return grilles are open and unblocked
  • Clear leaves, grass clippings, snow, or debris away from the outdoor coil

When to call a technician

Low pressure almost always means the system has lost refrigerant. Refrigerant work is EPA-regulated - call a licensed technician.

A LG mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Other LG codes