227 on a NIBE heat pump: Sensor fault (outdoor unit): Heat pump (outdoor unit) sends sensor fault message to the controller [other NIBE documents: Outdoor unit sensor not connected/defective / Sensor fault BT3/BT12/BT14/BT15/BT16/BT17/BT28/BT81/BP8/BP9/BP11/BT84 (outdoor codes 34,36,38,40,42,44,46,48,50,52,54,56)]
Short answer
On a NIBE heat pump, 227 means: Sensor fault (outdoor unit): Heat pump (outdoor unit) sends sensor fault message to the controller [other NIBE documents: Outdoor unit sensor not connected/defective / Sensor fault BT3/BT12/BT14/BT15/BT16/BT17/BT28/BT81/BP8/BP9/BP11/BT84 (outdoor codes 34,36,38,40,42,44,46,48,50,52,54,56)]. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 2 sources
What it means
The manuals for this range word it in different ways:
- Sensor fault (outdoor unit): Heat pump (outdoor unit) sends sensor fault message to the controller [other NIBE documents: Outdoor unit sensor not connected/defective / Sensor fault BT3/BT12/BT14/BT15/BT16/BT17/BT28/BT81/BP8/BP9/BP11/BT84 (outdoor codes 34,36,38,40,42,44,46,48,50,52,54,56)].
- The fuse in the heat pump has tripped: The inverter's fuse has tripped.
Part involved: temperature/pressure sensor; inverter and compressor drive.
When it shows: Heat pump (outdoor unit) sends sensor fault message to the controller; Outdoor unit sensor not connected/defective; Sensor fault BT3/BT12/BT14/BT15/BT16/BT17/BT28/BT81/BP8/BP9/BP11/BT84 (outdoor codes 34,36,38,40,42,44,46,48,50,52,54,56); Sensor fault BT3/BT12/BT14/BT15/BT16/BT17/BT28/BT81/BP8/BP9/BP11/BT84 The inverter's fuse has tripped.
Likely causes:
- F2120: Sensors incorrectly placed; open circuit or short circuit on sensor input | F2120: Open circuit or short circuit on sensor input.
- S2060: Current too high.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Resetting itself: no/unknown - Compressor blocked.
Manual reset: Reset from the controller alarm menu ('reset alarm' / 'Reset alarm and try again'); alarm recurs if the cause remains.
What you can check
- Read the alarm text and the 'info/action' help on the controller display (VVM/SMO or S-series smartguide). NIBE's manuals let the homeowner select 'reset alarm' ('Reset alarm and try again' on S-series); if the lamp returns to normal the alarm has cleared. If it comes back, do not keep resetting: select 'aid mode' ('Auxiliary operation' on S-series) if offered, so any electric additional heat keeps heat/hot water going, and contact your installer.
- Read the alarm text and the 'info/action' help on the controller display (VVM/SMO or S-series smartguide). NIBE's manuals let the homeowner select 'reset alarm' ('Reset alarm and try again' on S-series); if the lamp returns to normal the alarm has cleared. If it comes back, do not keep resetting: select 'aid mode' ('Auxiliary operation' on S-series) if offered, so any electric additional heat keeps heat/hot water going, and contact your installer. Check the heat pump and indoor unit breakers/RCD at the consumer unit are on; if one trips again, leave it off and call an engineer.
What the engineer will check
- Check sensor and its connections/wiring against the wiring diagram; measure sensor resistance against the NIBE temperature/resistance table; check the relevant PCB input. NIBE lists: Open circuit or short circuit on sensor input; defective sensor; Sensors incorrectly placed; open circuit or short circuit on sensor input; Open circuit or short circuit on sensor input.
- Check main and group fuses and cable connections, supply voltage under load, inverter terminal blocks, inverter mounting/cooling paste, compressor wiring and compressor. NIBE lists: Current too high.
Who to ask for: NIBE-trained heat pump installer (NIBE PRO / VIP); NIBE-trained heat pump engineer and/or qualified electrician.
Certification: Electrical work to BS 7671 by a competent person; Electrical work to BS 7671 by a competent electrician (notifiable work under Part P in England & Wales).
What you might notice
Sources
- TECHNICAL INFORMATION - ALARM LIST SMO 40 (TIF EN 2042-1, M12658EN) ↗ · TIF EN 2042-1 M12658EN · page 5 · Reviewed 23 September 2026
- Installer manual Air/water heat pump NIBE S2060 UK 1x230V IHB EN 2623-3 (831281) ↗ · IHB EN 2623-3 · page 30 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026