271 on an iDM Energiesysteme TERRA SW: Bivalent generator manually activated: Information that the bivalent (backup) generator was manually activated - reminder to switch it off to avoid high running costs
Short answer
On an iDM Energiesysteme heat pump, 271 means: Bivalent generator manually activated: Information that the bivalent (backup) generator was manually activated - reminder to switch it off to avoid high running costs. The heat pump keeps running. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Bivalent generator manually activated: Information that the bivalent (backup) generator was manually activated - reminder to switch it off to avoid high running costs.
Part involved: Bivalent generator manually activated.
When it shows: Information that the bivalent (backup) generator was manually activated - reminder to switch it off to avoid high running costs.
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Information only |
| Engineer needed? | Yes |
The heat pump keeps running.
What you can check
- Note the fault number and text shown after tapping the fault symbol on the Navigator display. 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