- Read the display message in the context of the current cycle or operating mode.
- Exit the mode, clear the option, or let the current function finish if that is how your model handles the message.
- Restart the appliance once if the display should have cleared but remains on screen.
Test-run protection display. On the LG AMNH12GB1A0, this code relates to the air conditioner and should be interpreted together with how the appliance is behaving right now.
- The air conditioner displays CH90 instead of normal status information.
- The current cycle, function, or startup sequence may stop, pause, or behave differently than expected.
- The same code may return after a reset if the underlying issue is still present.
- The appliance is reporting an active mode, reminder, or temporary operating condition.
- A recent button press, feature selection, or cycle state triggered the display message.
- Check the user manual or model-specific support guidance for the exact meaning of the displayed state.
- Confirm no child-lock, Sabbath mode, delay timer, or special feature is still active.
- If the same code remains after the normal mode should have ended, move to support or service advice.
- Do not force resets repeatedly if the appliance is still mid-cycle or in a protected state.
Contact support if CH90 stays visible after the normal mode should have cleared, or if the air conditioner will not return to normal operation.
Can CH90 clear after a reset?
Sometimes a temporary glitch clears after one full reset, but a repeated return usually means the same underlying issue is still there.
Should I keep using the appliance if it works again briefly?
Only if the code stays away and the appliance behaves normally. If the same code comes back, stop and move to service or more targeted diagnosis.