Pd on a Worcester Bosch Bosch Compress 2000 AWF: Alarm table: Unit T3 over-temperature protection / Troubleshooting table: Protection for high refrigerant outlet temperature in the finned coil in cooling mode
Short answer
On a Worcester Bosch heat pump, Pd means: Alarm table: Unit T3 over-temperature protection / Troubleshooting table: Protection for high refrigerant outlet temperature in the finned coil in cooling mode. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Alarm table: Unit T3 over-temperature protection / Troubleshooting table: Protection for high refrigerant outlet temperature in the finned coil in cooling mode.
Part involved: T3 coil temperature (cooling).
When it shows: Unit T3 over-temperature protection.
Likely causes:
- Heat exchanger cover attached; dirty/obstructed heat exchanger; insufficient space around unit; installation issue; faulty fan motor.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: yes.
Manual reset: Manual 13.2: switch the unit off and on again to reset the safety device; if reset fails contact dealer. Manual 11.4 warns repeated resets can cause irreversible damage.
What you can check
- Read and note the full code (and sub-code) shown on the controller and pass it to your installer.
- Check the outdoor unit is not blocked by leaves, snow, ice or other debris (do not open the casing).
- Manual 13.2: one off/on restart may be tried; if the code returns, stop and call an engineer - repeated resets can damage the unit.
What the engineer will check
- Review installation clearances; check fan motor.
Who to ask for: F-gas refrigeration engineer / heat pump installer.
Certification: F-gas certification (Category I) required for refrigerant circuit work; qualified electrician for electrical work.
What you might notice
What owners and engineers report
1 owner and engineer report mentions this.
- Keeps stopping / cutting out on the Bosch Compress 2000 AWF (R32 all-in-one monobloc): 1 report
Sources
- Installation and operating instructions Compress 2000 AWF CS2000AWF 4-30 R-S/T ↗ · 6721859133 (2025/10) · page 128; 138 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026