ao-smith ESST-52 200 Water Heater Error Codes
ESST-52 200 Error Code Reference
Section titled “ESST-52 200 Error Code Reference”Electric, 50 gal
| Error Code | Fault Description |
|---|---|
| E02 | Temperature sensor (thermistor) open or short circuit |
| E03 | ECO (high-limit) safety switch tripped |
| E04 | Upper heating element failure (electric models) |
| E05 | Lower heating element failure (electric models) |