30053 on a Stiebel Eltron WPM heat pump manager / WPMsystem: At least two assemblies with the same bus ID are present on the bus system
Short answer
On a Stiebel Eltron heat pump, 30053 means: At least two assemblies with the same bus ID are present on the bus system. 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: At least two assemblies with the same bus ID are present on the bus system.
Part involved: bus/communication cabling.
When it shows: At least two assemblies with the same bus ID are present on the bus system.
Likely causes:
- Remove the cause. Then carry out a reset of the heat pump.
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.
What the engineer will check
- Remove the cause. Then carry out a reset of the heat pump.
Who to ask for: Heat pump service engineer (electrical/controls).
Certification: Qualified electrician competence for live-work on appliance electrics.
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