Hitachi Error Codes

01

Indoor protection device tripped

Cause:

Drain float, freeze etc.

Action:

Read indoor sub-alarm; clear drain or airflow issue.

02

Outdoor protection device tripped

Cause:

HP switch or similar

Action:

Check HP switch, charge and condenser.

03

Indoor ↔ outdoor communication failure

Cause:

1-2 comms cable or PCB

Action:

Check 1-2 wiring polarity and PCBs.

04

Inverter ↔ control PCB comms failure

Cause:

Internal outdoor comms loss

Action:

Re-seat ribbon between PCBs; replace if needed.

05

Power source phase abnormal (3-ph)

Cause:

Phase loss / reverse

Action:

Swap two phases or repair supply.

06

Voltage drop on inverter

Cause:

Low DC bus / mains

Action:

Measure supply and DC bus.

07

Decrease in discharge gas superheat

Cause:

EEV overfeed / overcharge

Action:

Check EEV stepping and charge.

08

Increase in discharge gas temperature

Cause:

Low charge / EEV closed

Action:

Check charge, EEV, Td sensor.

0B

Outdoor air thermistor fault

Cause:

Open / short OAT sensor

Action:

Replace OAT thermistor.

0C

Outdoor coil thermistor fault

Cause:

Open / short coil sensor

Action:

Replace coil thermistor.

0D

Discharge gas thermistor fault

Cause:

Open / short Td sensor

Action:

Replace Td sensor.

11

Indoor return air sensor fault

Cause:

Open / short return sensor

Action:

Replace return air thermistor.

12

Indoor outlet air sensor fault

Cause:

Open / short outlet sensor

Action:

Replace outlet air thermistor.

13

Indoor freeze protection thermistor fault

Cause:

Open / short coil sensor

Action:

Replace freeze thermistor.

14

Indoor gas pipe thermistor fault

Cause:

Open / short gas pipe sensor

Action:

Replace gas pipe thermistor.

19

Indoor fan motor protection

Cause:

Stalled / overheated fan

Action:

Test motor; check airflow.

31

Indoor/outdoor capacity setting incorrect

Cause:

DIP setting mismatch

Action:

Set DIP per install manual.

38

Outdoor protection circuit abnormal

Cause:

PCB protection input fault

Action:

Check protection inputs / PCB.

EE

Compressor protection alarm

Cause:

Repeated compressor trips

Action:

Investigate prior alarms; service compressor circuit.