237 on an iDM Energiesysteme TERRA SW: Charging pump fault in bivalent operation: Fault contact of the charging pump tripped during operation of the bivalent (second) heat generator
Short answer
On an iDM Energiesysteme heat pump, 237 means: Charging pump fault in bivalent operation: Fault contact of the charging pump tripped during operation of the bivalent (second) heat generator. 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: Charging pump fault in bivalent operation: Fault contact of the charging pump tripped during operation of the bivalent (second) heat generator.
Part involved: Charging pump fault in bivalent operation.
When it shows: Fault contact of the charging pump tripped during operation of the bivalent (second) heat generator.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
What you can check
- Note the fault number and text shown after tapping the fault symbol on the Navigator display. Check the heating-system pressure gauge is in the range given in the user guide - do not top up yourself unless you have been shown how; check radiator/underfloor valves and room thermostats are open. If the fault recurs several times, contact iDM customer service/your installer.
What the engineer will check
- Diagnose per iDM service documentation for the unit (not obtained): check the monitored circuit/component named in the fault.
Who to ask for: heat pump engineer.
What you might notice
Sources
- IDM Wärmepumpen mit Navigatorregelung 2.0 - Bedienungsanleitung (812152 Rev.3) ↗ · 812152 Rev.3 · page p.72 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026