Error code
18 External communication fault
How it shows on the unit LED1 green 1 blink; LED2 orange 8 blinks; LEDs use 0.5 s on/0.5 s off
Applies to 3 models
ASEH09KHCBN, ASEH12KHCBN, ASEH14KHCBN
What this means
Communication fault involving an external device or interface.
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.
See the official Fujitsu manualA deep link to the manufacturer's own PDF for full technical detail. We link to manuals, we never host them.
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