Hitachi 01800 fault code
Hitachi air conditioning
What the Hitachi 01800 fault code means, from the manufacturer's own service literature, and the UK models it applies to.
What it means
RAK-PSE 'Frost Wash' / auto-clean cycle could not complete. Not a refrigerant fault — the cleaning mechanism or its sensing is the issue. (RAK-PED has no auto-clean and does not raise this.)
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 01800 on that machine.
Wall-mounted49
Cassettes36
Ducted35
Ceiling suspended7
Ceiling or floor8
Floor consoles6
Floor-standing8
Indoor and outdoor pairs2
Multi-split outdoor units7
Outdoor units63
01800 on these comes from each model's own manual, which may not match the meaning above — tap yours to read it.
Now the harder half: proving what caused it
01800 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 01800 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.
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Related codes
- 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)
- 01300Data reading error (PSE: EEPROM · PED: IC401) (code 13)
- 01301EEPROM reading error (code 13)
- 01401Active converter defective (code 14)
- 01501Abnormal PWB circuit (code 15)
- 01601High load stop (code 16)
- 02000Human sensor defective (code 20) — RAK-PSE models