Trane TVR Pro CO Series Service Manual page 88

2.14 H7: Unmatched total number of indoor units
Digital display output
Description
 Number of indoor units detected by master unit not same as number set on main PCB.
 All units stop running.
 Error code is only displayed on the master unit.
Trigger / recover condition
 Trigger condition: Only one indoor unit cannot be detected by master unit for 8 hours or more than one indoor unit
cannot be detected by master unit for 3 minutes.
 Recover condition: Number of indoor units detected by master 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.
87