Stiebel Eltron Tempra Plus and Accelera 300 E display numeric error codes on their control panels. Tempra Plus uses Exx-style codes; Accelera uses combination letter+number codes.
Tempra Plus error codes
| Code | Meaning | Action |
|---|---|---|
| E1 | No water flow detected | Check flow rate, inlet filter, flow sensor |
| E2 | Element / heating fault | Element ohm test; check breaker |
| E3 | Outlet temperature sensor | NTC sensor test; replace if open/shorted |
| E4 | Inlet temperature sensor | NTC sensor test; replace if open/shorted |
| E5 | Pressure switch fault | Internal pressure sensor; contractor diagnosis |
| E6 | Overtemperature lockout | Cool-down + reset; if recurs, control board |
Accelera 300 E error codes
| Code | Meaning | Action |
|---|---|---|
| Various | See Accelera-specific guide | Heat pump compressor, sensors, mode |
How to read codes
- Tempra Plus: code appears on digital display when fault is active. Cycle power to clear soft faults; some faults require contractor diagnosis
- Accelera: code appears on control panel display; fault history accessible via menu
How to reset
- Tempra Plus: turn breakers off for 30 seconds, then on. This clears soft faults
- Accelera: press reset on the control panel; some faults require breaker cycle
- SHC mini-tank ECO: red reset button on rear panel; press to reset thermal cutoff
DHC and Mini diagnostics
DHC and Mini point-of-use units don\'t have digital displays. Diagnosis is by symptom:
- No hot water — verify electrical, flow rate, inlet filter
- Hot but inadequate — element burned; full unit replacement on Mini (integrated element)
- Hot but inconsistent — flow sensor or pressure switch
Bottom line
Tempra Plus codes are diagnostic — they tell you where to start. Most resolve with simple actions (filter clean, breaker reset, sensor swap). Stiebel tech support (1-800-582-8423) excellent for code interpretation if unclear.