motor-p-error on a Danfoss DHP-H: Deployed overload relay (overcurrent relay) for compressor or outdoor-unit fan; on certain models alarms from the brine pump or soft starter can also occur. Compressor stopped
Short answer
On a Danfoss heat pump, motor-p-error means: Deployed overload relay (overcurrent relay) for compressor or outdoor-unit fan; on certain models alarms from the brine pump or soft starter can also occur. Compressor stopped. 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: Deployed overload relay (overcurrent relay) for compressor or outdoor-unit fan; on certain models alarms from the brine pump or soft starter can also occur. Compressor stopped.
Part involved: motor protection (overcurrent relay F11), soft starter.
Likely causes:
- Phase drop or blown fuse; defective soft starter (3-phase or 1-phase); defective or incorrectly set motor protection; cable break; defective compressor (3-phase); overload alarm from brine pump (certain models); single-phase soft-starter alarm (check LEDs).
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Manual reset: Set operating mode OFF then back to the desired mode.
What you can check
- Note the exact alarm text. The manual allows acknowledging by setting the operating mode to OFF and then back to the previous mode - do this once; if the alarm returns, leave it and call an engineer. Check the heat pump's breaker/isolator at the consumer unit is on and has not tripped.
What the engineer will check
- Check all phases at incoming terminal block and fuses; check soft-starter output when I/O card signals (A1-A2); clamp-meter compressor current vs motor-protection setting; check compressor winding resistances; check brine pump WSK switch; read soft-starter LEDs.
Who to ask for: heat pump engineer.
Certification: Qualified electrician / heat pump engineer (electrical fault-finding).
What you might notice
Sources
- Service instructions DHP-A, DHP-A Opti, DHP-AL, DHP-AL Opti, DHP-C, DHP-H, DHP-H Opti, DHP-H Opti Pro, DHP-L, DHP-L Opti, DHP-L Opti Pro (VMGFC302) ↗ · VMGFC302 (© 2010; PDF regenerated 2024-07-10 on assets.danfoss.com) · page printed p.35, pp.41-42 (Table 15); PDF pp.37, 43-44 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026