Error code
H 64 Outdoor high-pressure sensor abnormality
How it shows on the unit TIMER indicator blinks when the unit has stopped
Applies to 4 models
CS-CZ25ZKE, CS-CZ35ZKE, CU-CZ25ZKE, CU-CZ35ZKE
What this means
The outdoor high-pressure sensor is reporting an abnormal condition.
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.
Using Claude Code or Meta Muse? Connect HeatPump AI and ask it about H 64.