Trane 4TVH0086FE000AA Service Manual page 107

2.13 H7: Unmatched total number of indoor units
Digital display output
Description
 Number of indoor units detected by the outdoor unit not same as number set on main PCB.
 All units stop running.
 Error code is displayed on the outdoor unit.
Trigger / recover condition
 Trigger condition: Only one indoor unit cannot be detected by the outdoor unit for 8 hours or more than one indoor
unit cannot be detected by the outdoor unit for 3 minutes.
 Recover condition: Number of indoor units detected by the outdoor unit is same as number set on main PCB.
 Reset method: Resume automatically.
Possible causes
 Number of indoor units set on main PCB not same as actual number of indoor units.
 Some indoor units are powered off.
 Communication wires between indoor and outdoor units not connected properly.
 Indoor unit PCB damaged.
 Indoor unit without address or indoor unit address duplicated.
 Main PCB damaged.
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