E21.RHP-info on a Worcester Bosch Greenstore LECP ground source heat pump: Temporary heat pump stop E21.RHP
Short answer
On a Worcester Bosch heat pump, E21.RHP-info means: Temporary heat pump stop E21.RHP. 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: Temporary heat pump stop E21.RHP.
Part involved: high pressure.
When it shows: Refrigerant pressure too high; repeated occurrences escalate to category A (Tripped high pressure switch).
Likely causes:
- Refrigerant pressure too high; repeated occurrences escalate to category A (Tripped high pressure switch).
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: Automatic.
What you can check
- Read and note the full alarm text and category letter shown on the controller and pass it to your installer.
What the engineer will check
- Diagnose per chapter 21: Refrigerant pressure too high; repeated occurrences escalate to category A (Tripped high pressure switch).
Who to ask for: ground source heat pump engineer.
Certification: F-gas certification for refrigerant circuit; competent person for electrical work.
What you might notice
Sources
- Installation, Commissioning and Servicing Instructions Worcester Greenstore LECP GSHP (System/Combi 6-11 kW) ↗ · 6 720 806 768 (2013/02) · page 63 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026