30054 on a Stiebel Eltron WPM heat pump manager / WPMsystem: The thermistor protection relay for the compressor has been triggered
Short answer
On a Stiebel Eltron heat pump, 30054 means: The thermistor protection relay for the compressor has been triggered. 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: The thermistor protection relay for the compressor has been triggered.
Part involved: compressor / expansion valve / pressure switches.
When it shows: The thermistor protection relay for the compressor has been triggered.
Likely causes:
- The intermediate injection is faulty. The thermistor chain has been interrupted. The compressor is faulty. The compressor has an interwinding fault. The motor overload relay is faulty. Remove the cause. Then perform a reset of the heat pump via the WPM.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: no.
Manual reset: yes - reset of heat pump via WPM after cause removed (contractor).
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
- The intermediate injection is faulty. The thermistor chain has been interrupted. The compressor is faulty. The compressor has an interwinding fault. The motor overload relay is faulty. Remove the cause. Then perform a reset of the heat pump via the WPM.
Who to ask for: F-gas/refrigeration-qualified heat pump engineer (R290/A3 flammable-refrigerant competence for R290 models).
Certification: F-gas certification for fluorinated refrigerants (R410A/R454C); flammable refrigerant (R290) handling training for R290 models.
What you might notice
Sources
- WPM notification list (WPM V2.9) - multilingual; English section pp.15-26 (DOC-00081866) ↗ · WPM V2.9 · page 22 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026