Heat pumps · Error codes · Carrier
27Carrier · AquaSnap / AquaSnap Plus 30AWH (R410A inverter monobloc, 2010-2018 generations)
27 on a Carrier AquaSnap / AquaSnap Plus 30AWH: Compressor lock
Short answer
On a Carrier heat pump, 27 means: Compressor lock. 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: Compressor lock.
Likely causes:
- Inverter board or compressor fault.
Is it safe?
Switch the heat pump off at its isolator and call an engineer.
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
What you can check
- Note the code/LED pattern and the model from the rating plate, then contact a heat pump/refrigeration engineer.
- Check the heat pump's breaker/isolator at the consumer unit is on.
What the engineer will check
- Read inverter board LED codes (manual §9.1/9.2) and check compressor/inverter.
Who to ask for: refrigeration / heat pump engineer.
Certification: F-gas certification (refrigerant circuit work) and electrical competence.
What you might notice
Sources
- Carrier 30AW AquaSnap Plus Reversible Inverter - Installation, Operation and Maintenance Instructions (air/water cycle heat pump), Order No. L010130H42 01.2017 (supersedes 12.2015) ↗ · L010130H42 01.2017 · page 26 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026