DIY HVAC Tools

LG mini split error code CH38

Refrigerant leak detected (low charge). Also shown as CH 38, CH38.

  • TypeFault
  • SystemRefrigerant circuit
  • Can I fix it?Homeowner checks, then maybe a tech

What CH38 means on a LG

The board concluded from coil temperatures that the refrigerant charge is low. On a new installation this points to a flare joint that did not seal or a service valve left closed; on an older system it means a leak.

On this platform, CH38 is a fault: something has failed or is disconnected and needs diagnosis.

Common causes

  • A leaking flare joint.
  • Service valves not fully open.
  • An incomplete charge at installation.
  • A genuine leak.

How to fix it yourself

Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician.

  1. Open both service valves fully.
  2. Leak-check every flare joint with soapy water while the system runs.
  3. Pull the front panel and check the filters and the indoor coil. Dirty filters and a matted coil restrict airflow, and airflow problems trigger a surprising number of protection codes.
  4. Anything inside the refrigerant circuit (sensors are fine, but valves, compressors and leaks are not) needs EPA-certified refrigerant handling. That is a technician job.

Switch off power at the breaker before opening either unit. Capacitors in the outdoor unit hold a charge for several minutes after power is cut.

When to call a technician

A technician must find the leak, repair, evacuate and recharge by weight.

Which LG units show CH38

This page applies to LG Art Cool, Standard, Mega and Multi F units. LG's own documentation lists CH38 as "Refrigerant leak detected (low charge)", the same definition used across the LG it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.

Where LG shows this code

The indoor display shows CH followed by a number (CH05, CH38). Units without a display blink the indicator lamps in a pattern; the outdoor board LEDs blink the same number. If someone tells you 'CH 5', that is CH05. CH01 to CH12 are indoor-unit faults, CH21 to CH29 are inverter and compressor faults, CH32 to CH38 are refrigerant-side protections, CH40 to CH48 are outdoor sensors, and CH51 to CH73 are outdoor-unit system faults.

Other LG codes

Same part of the system as CH38:

CH24High or low pressure switch operatedCH34High pressure too high (pressure sensor)CH35Low pressure too low (pressure sensor)CH61Condenser pipe temperature too high
CH01Indoor air (room) temperature sensor fault (open or short circuit)CH02Indoor inlet pipe temperature sensor fault (open or short circuit)CH03Communication error with the wired remote controllerCH04Drain pump or float switch faultCH05Communication error between indoor and outdoor unitsCH06Indoor outlet pipe temperature sensor fault (open or short circuit)CH07Operating mode conflict (multi-split)CH09Indoor unit EEPROM error

All LG error codes

Questions people ask

Can I reset a LG CH38 code myself?

Yes. Turn the system off at the breaker for five minutes, then restart it. If CH38 comes back, the fault is real and needs the checks above.

Is it safe to keep running a LG showing CH38?

The unit will usually refuse to run, or run with reduced output, until the fault is cleared. Repeated resets do not fix anything and can mask a problem that is getting worse.

Do I need a technician for LG CH38?

Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician. A technician must find the leak, repair, evacuate and recharge by weight.

Sources

  • LG residential split service manuals (error code tables)

Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.