30493 on a Stiebel Eltron WPM heat pump manager / WPMsystem: I2C sensor value of the "Exhaust air differential pressure sensor" outside the permissible range
Short answer
On a Stiebel Eltron heat pump, 30493 means: I2C sensor value of the "Exhaust air differential pressure sensor" outside the permissible range. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: I2C sensor value of the "Exhaust air differential pressure sensor" outside the permissible range.
Part involved: ventilation module / fans / air sensors.
When it shows: I2C sensor value of the "Exhaust air differential pressure sensor" outside the permissible range.
Likely causes:
- Check sensor, lead and relevant plug-in connectors. Replace if faulty.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Warning |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Resetting itself: unknown.
Manual reset: unknown.
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 heating system pressure gauge reading is in the normal range stated by your installer.
What the engineer will check
- Check sensor, lead and relevant plug-in connectors. Replace if faulty.
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 25 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026