Fujitsu A4.3

Medium

Airstage V-II — High pressure protection 2 (Error code A4.3).

Fujitsu A4.3: High pressure protection 2 (Error code A4.3). This fault usually isn't an immediate stop, but should be checked soon.

Possible causes

Condenser/evaporator poor air circulation (dirty/blocked).
Refrigerant undercharge or overcharge.
Pressure switch/sensor faulty.

Check steps

Clean heat exchanger, check airflow.
Check refrigerant charge/pressures.
Test pressure switch/sensor.

Affected parts

Druckschalter
Wärmetauscher

Safety note

Refrigerant under pressure — use PPE.

Source: Fujitsu Airstage V-II VRF Service Manual, "Error Code List For Outdoor Unit" p.65 + "Trouble Shooting With Error Code (Outdoor Unit)" p.82ff (ManualsLib scan of official manual)

Reviewed by Anıl Güzeldemir — in the refrigeration machine room since 2006, developer of Enthalio.

Look up in Enthalio →

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