A.O. Smith ENS/ENT HVAC System Error Codes
High-Efficiency HVAC System.
10 error codes documented.
Severity breakdown:
3 critical , 7 warning
Error Codes
| Code | Description | Severity |
| E06 | Flammable Vapor Detection | Critical |
| E4 | High Temperature Cutoff | Critical |
| ECO | Emergency Cutoff | Critical |
| E1 | Thermistor Failure | Warning |
| E2 | Dry Fire Protection | Warning |
| E3 | Sensor Fault | Warning |
| E5 | Communication Error | Warning |
| LOC | Controls Locked | Warning |
| LWR | Lower Element Fault | Warning |
| UPR | Upper Element Fault | Warning |
Cross-Reference: Shared Codes with Other A.O. Smith Models