Hitachi AC Error Codes: What Each Code Means and How to Fix It
Hitachi air conditioners display E-series error codes (E01, E02, E03 and so on) on the indoor unit display when a fault is detected. This guide covers every common Hitachi AC error code with the cause and the fix to try at home before calling a Hitachi service technician.
Hitachi AC Error Code Table
| Code | Meaning | Fix |
|---|---|---|
| E01 | Indoor room temperature sensor fault | Check sensor connector; replace sensor if faulty |
| E02 | Indoor coil temperature sensor fault | Inspect connector on indoor PCB; replace sensor |
| E03 | Outdoor coil temperature sensor fault | Inspect outdoor sensor; replace if faulty |
| E06 | Communication error (indoor–outdoor) | Power cycle both units; inspect inter-unit signal wiring |
| E08 | Indoor fan motor fault | Check fan blade for obstruction; replace fan motor |
| E09 | Indoor EEPROM / memory error | Power cycle; replace indoor PCB if error persists |
| E18 | High pressure protection | Clean condenser coil; ensure clear airflow around outdoor unit |
| E19 | Low pressure / refrigerant fault | Check for refrigerant leak; call technician for gas check |
| E20 | Discharge temperature too high | Turn off AC; clean outdoor unit; check refrigerant level |
| E25 | Overload protection | Check power supply voltage; possible compressor issue |
| E40 | Outdoor unit PCB fault | Power cycle; technician inspection for outdoor PCB |
Top Hitachi AC Error Codes Explained in Detail
E06 — Communication Error
E06 is the most common Hitachi AC error code. It means the indoor unit cannot communicate with the outdoor unit. After a power failure or voltage fluctuation, this is often a temporary fault — turn off the AC breaker for 3 minutes, then restore power. If E06 comes back immediately, the inter-unit signal cable may be damaged or the PCB on one unit may have failed.
E18 — High Pressure Protection
Hitachi E18 fires when refrigerant pressure on the high side becomes excessive. A clogged outdoor condenser coil is the most frequent cause in India — dust and debris build up over months and block heat dissipation. Turn off the AC, clean the outdoor unit fins with a brush or gentle water spray, confirm there is clear space around the unit, and restart. If E18 persists, the refrigerant may be overcharged.
E19 — Low Pressure / Refrigerant Fault
E19 indicates the refrigerant charge is low, usually due to a slow leak in the system. Symptoms include poor cooling and ice forming on the indoor copper pipe. Stop running the AC and contact Hitachi service (1800-102-3344) — a technician must find the leak, repair it, and recharge the refrigerant.
E08 — Indoor Fan Motor Fault
E08 appears when the indoor blower fan is not running at the expected speed. First, check whether anything is obstructing the fan through the front grille. If there is no obstruction and the fan is not spinning, the motor capacitor or motor itself needs replacement — a straightforward and affordable repair.
How to Reset a Hitachi AC After an Error
- Press the power button on the remote to switch off the AC.
- Turn off the dedicated circuit breaker for the AC.
- Wait 2–3 minutes.
- Restore power and switch the unit back on.
- If the same error code appears, schedule a service call with Hitachi.
When to Call a Technician
- E19 low-pressure error — refrigerant system repair needed.
- E20 discharge temperature error — compressor at risk.
- E25 overload that keeps coming back — compressor inspection.
- E40 outdoor PCB fault — board-level repair or replacement.
- Any sensor code (E01, E02, E03) that does not clear after reset.
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