LG CH38 Error Code: Low Refrigerant — Causes & Fix (2026)
🕒 Last updated:
LG CH38 — quick diagnosis
CH38 = low refrigerant (usually a leak) or unstable power. On some models it shows as F4. Confirm against your model's manual.
| Likely cause | How to spot it | What to do |
|---|---|---|
Low refrigerant (a leak) | Weak cooling, CH38 returns after reset | Technician — find & repair the leak, recharge (EPA 608) |
Unstable / wrong power | CH38 after a power event | Confirm a dedicated, stable circuit; power-cycle once |
Temporary power glitch | CH38 clears after a reset | Power-cycle 5 min — if it stays clear, you're done |
Leak ignored / topped up | CH38 keeps coming back | Don't just recharge — the leak must be repaired |
The LG CH38 error code means your system has detected low refrigerant — usually a leak — or, less often, an electrical fault from unstable power. The key thing to understand: a mini split’s refrigerant circuit is sealed, so it doesn’t get “used up.” If the system is low, the refrigerant has leaked out, typically through a crack in the copper line, a loose flare connection, or a failed joint. On some LG models the same fault appears as F4. The only safe homeowner step is one power cycle (in case it was a temporary power glitch) and confirming the unit has stable, dedicated power. If CH38 returns, it points to a refrigerant leak — and that requires a licensed, EPA-608-certified technician, not a DIY fix. Here’s what’s going on and why.
What the LG CH38 code means
CH38 is a protection code: the system sees that refrigerant pressure/charge is too low (or that the power supply is unstable) and stops to protect itself. Because the circuit is sealed, “low refrigerant” = a leak. Running a unit low on refrigerant makes it cool poorly and can overheat the compressor — the most expensive part — so it’s not a code to ignore or repeatedly reset.
Common causes
- Refrigerant leak — a crack in the copper line, a loose flare nut, or a failed joint (the most common cause). Often follows weak cooling.
- Unstable or incorrect power — CH38 can also flag an electrical/voltage problem, so a dedicated, correctly sized circuit matters.
- A temporary glitch — occasionally a one-off power event sets it and a reset clears it.
How to fix an LG CH38
- Power-cycle once — off at the breaker for ~5 minutes, then back on. If CH38 was a temporary power glitch, it clears and stays clear.
- Check the power — confirm a stable, correctly sized dedicated circuit.
- If CH38 returns, stop running the unit in that mode and call an EPA-608 technician to find and repair the leak, then recharge. If you also see weak cooling or ice, read mini split not cooling.
When to call a professional
Looking at a different LG code? Our full LG error-code guide covers the CH-code list.
Sources
- LG Support — air-conditioner error-code guides (CH38 / inspection code: low refrigerant and power-related diagnostics). Confirm the exact steps for your model number.
Trademark note: “LG” is a trademark of LG Electronics. This page is an independent homeowner resource and is not affiliated with, authorized by, or endorsed by LG. Brand and code references are used factually for identification and troubleshooting only.
Frequently asked questions
What does the LG CH38 error code mean?
CH38 means your LG system has detected low refrigerant — usually a leak — or an electrical fault from unstable power. Because the refrigerant circuit is sealed, "low refrigerant" almost always means it has leaked out through a crack or loose connection, not that it was simply used up. On some models the same fault shows as F4.
How do I fix an LG CH38 error?
Start with one power cycle: turn the unit off, switch its breaker off for about 5 minutes, then restore power — this clears a CH38 caused by a temporary power glitch. If CH38 comes back, it indicates low refrigerant (a leak), and an EPA-608-certified technician must locate the leak, repair it, and recharge the system. That part is not a DIY repair.
Is the LG CH38 code serious?
It can be. Low refrigerant means the sealed system has a leak, and running the unit low on refrigerant can overheat and damage the compressor — the most expensive part. It's best to stop running the unit in that mode and have the leak found and fixed promptly rather than topping it up and ignoring the cause.
Why is my LG low on refrigerant if the system is sealed?
A mini split's refrigerant doesn't get "used up" — the circuit is sealed. So if it's low, it has leaked out, typically through a crack in the copper line, a loose flare connection, or a failed joint. That's why simply recharging without finding the leak only works temporarily; the leak has to be repaired.
Can I fix LG CH38 myself?
You can safely try one power cycle and confirm the unit has stable, dedicated power. Anything beyond that involves the sealed refrigerant circuit, which legally requires EPA Section 608 certification and proper equipment to handle — so leak repair and recharging must be done by a licensed technician.