LG Mini-Split Code CH73
Soft lockoutShown as: Outdoor LED01 (red) blinks 7 times, LED02 (green) blinks 3 times
PSC / PFC overcurrent error detected in software - the outdoor unit's power factor correction stage saw a current peak beyond its limit. Same protection as CH27 but caught by the firmware rather than the hardware trip.
Manual wording: “PSC / PFC overcurrent error (SW)”
Documented for: All LG residential mini-split outdoor units
Likely causes, most common first
- Overload operation - outdoor fan restricted, screened, or blocked
- Bad reactor fastening
- Burned PCB internal parts (PSC module)
What you can safely check yourself
- Clear leaves, grass clippings, snow, or debris away from the outdoor coil and fan
- Check and clean the indoor air filters
- Turn the system off at the breaker for three minutes and back on
When to call a technician
The PFC stage and reactor are inside the live inverter section of the outdoor unit. Call a technician.
A LG mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Single Zone Four-Way Ceiling-Cassette Installation Manual (LG Electronics U.S.A., Inc., Single-zone four-way ceiling cassette indoor units with LUU090HV through LUU420HV outdoor units) · checked 2026-08-25
- Convertible Mid-Static Ducted LGRED Degree System Installation Manual (LG Electronics U.S.A., Inc., LGRED single-zone convertible mid-static ducted indoor units with LUU180HHV / LUU240HHV outdoor units) · checked 2026-08-25
- MULTI F / MULTI F MAX Outdoor Unit Installation Manual (LG Electronics U.S.A., Inc., Multi F and Multi F MAX multi-zone heat pump outdoor units (LMU series) with standard wall-mount, Art Cool, cassette and ducted indoor units) · checked 2026-08-25