20310 on a Stiebel Eltron WPM heat pump manager / WPMsystem: Major inverter fault: Supply air fan motor excess current shutdown function
Short answer
On a Stiebel Eltron heat pump, 20310 means: Major inverter fault: Supply air fan motor excess current shutdown function. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Major inverter fault: Supply air fan motor excess current shutdown function.
Part involved: ventilation module / fans / air sensors.
When it shows: Major inverter fault: Supply air fan motor excess current shutdown function.
Likely causes:
- Inverter fault.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: yes - heat pump restarts after idle time (~10-12 min); locks out after 5 faults in 2 h run.
Manual reset: after 5 faults in 2 h: IWS/WPM reset.
What you can check
- Read and note the full message code and time from the WPM display (DIAGNOSIS / NOTIFICATIONLIST if accessible without a code).
- Check the heat pump and controller circuit breakers/isolators at the consumer unit are on.
- Check the outdoor unit air intake/discharge is not blocked by leaves, snow or ice (air source units).
What the engineer will check
- Inverter fault.
Who to ask for: MVHR/ventilation-competent heat pump engineer.
What you might notice
Sources
- WPM notification list (WPM V2.9) - multilingual; English section pp.15-26 (DOC-00081866) ↗ · WPM V2.9 · page 19 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026