Brand: HITACHI
Category: Refrigerator
Document Type: Parts/Service
Language: EN
Parts/Service for R-Z660ERU9X
Uploaded: Nov. 21, 2025, 6:36 p.m.
Manual Publish Date: 2011-01-01
Basic Operation (Time Chart)
The refrigerator operates in cycles based on temperature sensor readings and door openings.
Compressor Operation: The compressor turns on when the F-sensor (freezer sensor) detects high temperatures (above -16°C) and turns off when it reaches low temperatures (below -22°C). It requires a minimum ON-time and OFF-time to maintain efficiency. The total ON-time can be a minimum of 12 hours.
Fan Operation: The R-Fan (refrigerator fan) operates intermittently, often for 30 seconds ON and 30 seconds OFF, or during compressor ON-time, to circulate cool air.
Defrosting: Defrosting occurs automatically, initiated and terminated by the system. A defrost heater is used for this process. Pre-cooling periods are also indicated.
Lamp and Door Switches: The interior lamps turn on when the doors are opened and off when closed. Door switches signal the status of the doors.
Troubleshooting and error codes
| Priority sequence | Error code (LED on PCB) | Breakdown list | Breakdown description | Operation |
|---|---|---|---|---|
| 1 | 1s ON + B link once | F-sensor abnormal | F-sensor value abnormal | Provisional mode |
| 2 | 1s 0 N + B link tw ice | R-sensor abnormal | R-sensor value abnormal | Provisional mode |
| 3 | 1s ON + B link 3 times | TC-sensor abnormal | TC-sensor value abnormal | Display error code |
| 4 | 1s 0 N + B link 4 times | D-sensor abnormal | D-sensor value abnormal | No defrosting |
| 5 | B link tw ice | EEPROM data abnormal | EEPROM data abnormal | Display error code |
| 6 | B link 12 times | R-Fan motor abnormal or 12V drops | R-Fan motor abnormal or 12V drops | R-Fan motor stops and retry after 3m in. |
| 7 | B link 4 tm es | Defrosting circuit abnormal | Defrosting continues even after 2 hours | After 2 hours, stop defrosting and display error code |
| 8 | 3s ON + B link once | Freezer not cool | F-sensor stays over -10°C for 72 hours | Display error code |
| 9 | 3s ON + B link tw ice | Refrigerator not cool | R-sensor stays over 10°C for 72 hours | Display error code |