CH38 - The air conditioner may be low on refrigerant.
LG says CH38 and F4 indicate the air conditioner is low on refrigerant gas. The warning is intended to protect the appliance from damage. If it appears after installation or relocation, LG points to refrigerant shortage or piping connection issues as likely areas for inspection.
Based on LG USA support articles for wall-mounted and related inverter split air conditioners; exact indicators and alternate code labels can vary by model.
Severity
High
Display
The fault may appear as CH38 or, on some models, as F4.
Support first?
Often not
Models in range
Wall-mounted inverter split air conditioners, 2-in-1 heating and cooling air conditioners
What to do first
Start with these checks
- 1If the code appeared after installation or relocation, contact the installer rather than continuing to run the unit.
- 2If it appeared during normal use, perform one 5-minute power reset as LG suggests.
- 3Do not try to add refrigerant or open the sealed system yourself.
Likely causes
What usually sits behind this code
Low refrigerant charge.
Piping connection issue after installation or relocation.
Temporary electrical instability if the code appeared during normal use and then clears after a reset.
Contact support
Contact customer support if any of these apply
- !CH38 or F4 returns after a power reset.
- !The unit was recently installed or relocated.
- !Cooling performance is poor together with the code.
- - LG describes this warning as a protection feature against appliance damage.
- - LG specifically mentions checking piping connections through the installation technician.
Related codes
Nearby codes in this family
More ranges
More LG air-conditioner ranges
Source notes
Source and scope
Source: LG USA Support
LG says CH38 or F4 means the unit is low on refrigerant and advises installer inspection after installation issues or service if the error persists.
Last reviewed: 2026-04-19
Refrigerant circuits are not user-serviceable. Limit action to a power reset and visible checks only.