Heat pumps · Error codes · Thermia
motor-p-comp-errorThermia · Atec
motor-p-comp-error on a Thermia Atec: The compressor motor protection has deployed
Short answer
On a Thermia heat pump, motor-p-comp-error means: The compressor motor protection has deployed. 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: The compressor motor protection has deployed.
Part involved: compressor motor protection, soft starter.
Likely causes:
- Phase drop or blown fuse; cable break; defective soft starter (3-phase or single-phase); defective/incorrectly set motor protection; defective compressor; single-phase soft-starter alarm. (causes from the equivalent Danfoss DHP-AQ service instructions VMGFJ202).
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. Check the heat pump's breaker/isolator at the consumer unit is on and has not tripped. Acknowledge once (operating mode OFF then back); if it remains, contact a service technician (user manual 086L0130 p.25).
What the engineer will check
- Check all phases and fuses; check soft starter releases phases when heat pump card signals (A1-A2 or ON-N); clamp compressor current vs setting; check windings; read soft-start LEDs.
Who to ask for: heat pump engineer.
Certification: Qualified electrician / heat pump engineer (electrical fault-finding).
What you might notice
Sources
- Service Instructions Atec (VIIFM102) - silo.tips copy ↗ · VIIFM102 · page p.10 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026