What CH04 Means
CH04 indicates a drainage problem, per LG's dedicated CH03/CH04 troubleshooting article, caused by a malfunctioning drain pump, a blocked or upward-sloping drain hose, or a dirty filter.
Common Causes of CH04
- Malfunctioning drain pump
- Blocked or upward-sloping drain hose
- Dirty air filter restricting condensate drainage
🔧 One Safe Check You Can Try
Unplug the air conditioner, or turn off its circuit breaker if you can't reach the plug, wait about five minutes, then restore power and check whether the error code has cleared.
⚠ Why You Shouldn't Go Further Than That
- Do not disassemble the unit yourself - drain pump and internal component work carries the same fire, shock, and injury warning LG gives for every CH code on this platform.
- If CH04 persists after a reset, stop using the unit and contact LG Support rather than continuing to run it.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.