Hitachi 00901 fault code
Hitachi air conditioning
What the Hitachi 00901 fault code means, from the manufacturer's own service literature, and the UK models it applies to.
What it means
Safety: Safe isolation before opening terminal covers — mains present on the interconnect.
Source: Hitachi Technical Catalogue §9.10 / §10.1.2 Error Code Information (RAK-PSES(W)/RAC-WSE — Hitachi UK; RAK-PED/RAC-WED — Hitachi R32 catalogue), both render-verified
UK models this code applies to
Tap yours to open 00901 on that machine.
Wall-mounted39
Cassettes28
Ducted24
Ceiling suspended7
Ceiling or floor8
Floor-standing8
Outdoor units61
00901 on these comes from each model's own manual, which may not match the meaning above — tap yours to read it.
Wall-mounted13
Cassettes8
Ducted11
Indoor and outdoor pairs2
Multi-split outdoor units7
Now the harder half: proving what caused it
00901 names a symptom, not a root cause. In the app, the same code opens a guided investigation: what to measure first, the expected values for your exact model, and an honest verdict — including “nothing in this machine is broken” when that's what the readings say.
Chase 00901 on your machine →Free, no sign-up. Pick the model: where we hold a chart for it, it takes you through one question at a time.
Or watch one get chased — free demo →Related codes
- 00401Compressor switching failure (code 04)
- 00501Overload lower-limit cut (code 05)
- 00601OH (overheat) thermistor temperature rise (code 06)
- 00701Abnormal outdoor thermistor (code 07)
- 00900Indoor thermistor defective (code 09)
- 01000Abnormal rotating numbers (indoor fan speed) (code 10)
- 01001Abnormal power source (code 10)
- 01101Fan stop for strong wind (code 11)
- 01200Communication error, indoor ↔ outdoor (code 12) — RAK-PSE models
- 01201Outdoor fan motor fault (code 12)