229 on a NIBE heat pump: Short operation times for compressor: Compressor has stopped three times in a row shortly after start [other NIBE documents: Operation stopped from indoor section after less than 5 minutes / Compressor operation shorter than 5 minutes 3 times in a row]
Short answer
On a NIBE heat pump, 229 means: Short operation times for compressor: Compressor has stopped three times in a row shortly after start [other NIBE documents: Operation stopped from indoor section after less than 5 minutes / Compressor operation shorter than 5 minutes 3 times in a row]. 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:
- Short operation times for compressor: Compressor has stopped three times in a row shortly after start [other NIBE documents: Operation stopped from indoor section after less than 5 minutes / Compressor operation shorter than 5 minutes 3 times in a row].
- High pressure alarm: High pressure switch BP1 (63H1) has tripped 5 times within 60 minutes [other NIBE documents: High pressure switch (63H1) deployed 5 times within 60 min or 60 min continuously / Heat pump (selected outdoor unit) sends fault message to controller].
Part involved: heating medium flow, charge pump, particle filter; pressure switches/sensors, expansion valve.
When it shows: Compressor has stopped three times in a row shortly after start; Operation stopped from indoor section after less than 5 minutes; Compressor operation shorter than 5 minutes 3 times in a row High pressure switch BP1 (63H1) has tripped 5 times within 60 minutes; High pressure switch (63H1) deployed 5 times within 60 min or 60 min continuously; Heat pump (selected outdoor unit) sends fault message to controller.
Likely causes:
- F2120: Flow problem or incorrect settings in VVM/SMO | F2120: Poor flow, poor heat transfer; incorrect settings for heating and/or hot water | S2125: Poor flow, poor heat transfer; incorrect settings for heating and/or hot water.
- S2060: Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; incorrectly connected expansion valve; service valve closed; defective baseboard AA2 (PWB1); low or no flow in heating; defective circulation pump; defective fuse F(4A) | F2050: Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; expansion valve not correctly connected; service valve closed; defective PWB1; low or no flow; defective circulation pump; defective fuse F(4A).
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 heating system pressure gauge and check that radiator/underfloor thermostats are not all closed; check heating and hot water temperature settings have not been changed.
- 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. Air source systems: check the outdoor unit is clear of leaves/snow/ice. Read the heating system pressure gauge and note the reading for your installer.
What the engineer will check
- Check heating medium flow (pump speed/settings, particle filter, air in system), heating curve and hot water settings, correct sensor placement and flow/return connections. NIBE lists: Poor flow or poor heat transfer; incorrect settings for heating and/or hot water; Flow problem or incorrect settings in VVM/SMO; Poor flow, poor heat transfer; incorrect settings for heating and/or hot water.
- Check heating medium flow, particle filter and circulation pump; check pressure switches/sensors, expansion valve, service valves and refrigerant charge (F-gas qualified). NIBE lists: Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; incorrectly connected expansion valve; service valve closed; defective baseboard AA2 (PWB1); low or no flow in heating; defective circulation pump; defective fuse F(4A); Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; expansion valve not correctly connected; service valve closed; defective PWB1; low or no flow; defective circulation pump; defective fuse F(4A).
Who to ask for: NIBE-trained heat pump installer (NIBE PRO / VIP); Heat pump engineer with F-gas qualification (NIBE-trained / NIBE PRO installer).
Certification: None specific beyond competent heat pump installer; electrical work to BS 7671; F-gas certification for refrigerant circuit work (plus flammable-refrigerant competence for R290/R32 models).
What you might notice
Sources
- TECHNICAL INFORMATION - ALARM LIST SMO 40 (TIF EN 2042-1, M12658EN) ↗ · TIF EN 2042-1 M12658EN · page 6 · 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