LG / System air conditioners

CH07 - Units connected in the same system are running in conflicting operating modes.

LG says CH07 can appear on ceiling-type air conditioners when units in different rooms are running in conflicting modes. LG's example is one room set to cooling while another is set to heating. The support guide says all connected units should be set either to heating or to cooling/dehumidification.

Based on LG USA support pages covering ceiling-mounted and system air conditioners; breaker layout, display style, and wiring arrangements can vary by installation.

Severity

Medium

Display

The code appears as CH07 when linked indoor units in the same system are set to incompatible modes.

Support first?

Often not

Models in range

Ceiling-mounted system air conditioners, Multi-room system air conditioners

What to do first

Start with these checks

1Check the mode setting for each connected indoor unit in the system.
2Set all linked units to heating, or set them all to cooling/dehumidification as LG advises.
3Retry operation after the modes match.

Likely causes

What usually sits behind this code

One room or indoor unit is set to heating while another is set to cooling.

One room or indoor unit is set to heating while another is set to dehumidification.

Connected units in the same system are not using a compatible shared mode.

Contact support

Contact customer support if any of these apply

!CH07 remains even after all connected units are set to compatible modes.
!You cannot identify which rooms or units are part of the same linked system.
!The controller will not allow mode changes or the fault keeps reappearing.

- LG says air purification and fan-only modes can be used without the same restriction.
- LG also gives a similar CH07 example for 2-in-1 heating and cooling models.

Related codes

Nearby codes in this family

CH05

The indoor and outdoor units are not communicating, often because the outdoor unit has lost power.

More ranges

More LG air-conditioner ranges

Wall-mounted split systems

Wall-mounted inverter split air conditioners, 2-in-1 heating and cooling air conditioners.

Source notes

Source and scope

Source: LG USA Support

LG says CH07 on ceiling-type and multi-unit systems means connected units are set to conflicting modes and should be matched.

Last reviewed: 2026-04-19

Limit troubleshooting to checking controller settings. If the system layout or control logic is unclear, use a qualified technician.