Error code
H12 Indoor/outdoor capacity mismatch
Applies to 4 models
CS-LZ25TKE, CU-LZ25TKE, CS-LZ35TKE, CU-LZ35TKE
What this means
The connected indoor and outdoor units, or their control boards, do not have a compatible capacity combination.
When to call a technician
This fault involves refrigerant, pressure, or electrical work that must be handled by a certified technician under EU F-gas rules. Do not attempt to open the refrigerant circuit, access mains wiring, or adjust pressure components yourself. Contact a qualified installer or servicer for this one.