Too-short-changeover-time-for-floor-heating on a Worcester Bosch Greensource Split HP Hydrolight / Hydrocomfort: Warning: Too short changeover time for floor heating
Short answer
On a Worcester Bosch heat pump, Too-short-changeover-time-for-floor-heating means: Warning: Too short changeover time for floor heating. 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: Warning: Too short changeover time for floor heating.
Part involved: heating/cooling changeover delay.
When it shows: Delay before/after set shorter than 7 hours (not recommended with UFH).
Likely causes:
- Delay before/after set shorter than 7 hours (not recommended with UFH).
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Warning |
| Engineer needed? | Yes |
The heat pump keeps running.
Resetting itself: yes.
Manual reset: Acknowledge by pressing the rotary selector (Acknowledge) on the Hydrolight/Hydrocomfort user interface.
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
- Adjust delay settings.
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