
Rinnai Error Code E4
Common error codes

Error Code E4 – Outdoor Unit Overheat
Rinnai Error Code E4 commonly indicates overheating or outdoor unit protection. Dirty outdoor coils, blocked airflow, or fan faults can cause this.
✅ Hycool Air Conditioning Sydney can diagnose Rinnai E4 faults and restore reliable outdoor operation. If E4 appears, contact Hycool.