Too-cold-for-heat-pump-operation on a Worcester Bosch Greensource Split HP Hydrolight / Hydrocomfort: Info: Too cold for heat pump operation
Short answer
On a Worcester Bosch heat pump, Too-cold-for-heat-pump-operation means: Info: Too cold for heat pump operation. 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: Info: Too cold for heat pump operation.
Part involved: outdoor temperature.
When it shows: Outdoor temperature below 'Block heat pump at low outdoor temperature' (factory -15 C); additional heat only.
Likely causes:
- Outdoor temperature below 'Block heat pump at low outdoor temperature' (factory -15 C); additional heat only.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Information only |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Resetting itself: yes.
Manual reset: Info symbol clears once read.
What you can check
- Read and note the full alarm text shown on the controller and pass it to your installer.
What the engineer will check
- Review bivalence setting.
Who to ask for: heat pump installer / controls engineer.
Certification: None specific; electrical isolation required before wiring checks.
What you might notice
Sources
- Installation, Commissioning and Servicing Instructions Greensource Hydrolight and Hydrocomfort (ODU 7.5-12) ↗ · 6 720 806 629 (2013/02) · page 66 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026