226 on a NIBE heat pump: Stove monitor activated: Stove monitor activated
Short answer
On a NIBE heat pump, 226 means: Stove monitor activated: Stove monitor activated. The heat pump keeps running.
Reviewed 23 September 2026 · 1 source
What it means
The manuals for this range word it in different ways:
- Stove monitor activated: Stove monitor activated.
- Inverter alarm type II: Incorrect inverter.
Part involved: AUX input / external control; inverter and compressor drive.
When it shows: Stove monitor activated Incorrect inverter.
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Information only |
The heat pump keeps running.
Resetting itself: yes - Only information.
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. Check whether any external equipment connected to the heat pump (e.g. energy supplier load control, smart thermostat or other AUX device) is signalling a block.
- 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 the device connected to the AUX input and the AUX input configuration.
- Check main and group fuses and cable connections, supply voltage under load, inverter terminal blocks, inverter mounting/cooling paste, compressor wiring and compressor.
Who to ask for: NIBE-trained heat pump installer (NIBE PRO / VIP); NIBE-trained heat pump engineer and/or qualified electrician.
Certification: None specific beyond competent heat pump installer; electrical work to BS 7671; 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 16 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026