HVAC Code Lookup

LG Mini-Split Code CH93

Soft lockout

Indoor / outdoor unit communication error. LG's consumer support page describes CH93 as a communication problem between the indoor and outdoor units; the service manual handles it with the same troubleshooting flow as CH05 and CH53.

Manual wording: “Indoor / outdoor unit communication error”

Documented for: LG single-zone room air conditioner / mini-split systems

Likely causes, most common first

  1. No power on the indoor unit
  2. Indoor/outdoor unit power connection error, or the communication line not installed
  3. Improper connection at the terminal block for the communication wire
  4. Improper wiring of the communication L-N wire between indoor and outdoor units
  5. Communication error caused by external electrical noise
  6. Indoor/outdoor communication circuit parts burned, or no power due to a burned indoor or outdoor PCB

What you can safely check yourself

  • Check the breakers for BOTH the indoor and outdoor unit are on and not tripped
  • Check the outdoor disconnect switch next to the condenser is switched on
  • Turn the system off at the breaker for three minutes, then back on

When to call a technician

If power is confirmed on at both units and CH93 stays, the interconnecting communication wiring or a control board needs a 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