313 on a NIBE heat pump: Dry running of circulation pump GP1 or GP2: Poor or no flow
Short answer
On a NIBE heat pump, 313 means: Dry running of circulation pump GP1 or GP2: Poor or no flow. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
0 sources
What it means
The manual says: Dry running of circulation pump GP1 or GP2: Poor or no flow.
Part involved: heating medium flow, charge pump, particle filter.
When it shows: Poor or no flow.
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 and circulation pump blocked. Manual reset.
Manual reset: Reset from the controller alarm menu ('reset alarm' / 'Reset alarm and try again'); alarm recurs if the cause remains - NIBE: Compressor and circulation pump blocked. Manual reset.
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.
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.
Who to ask for: NIBE-trained heat pump installer (NIBE PRO / VIP).
Certification: None specific beyond competent heat pump installer; electrical work to BS 7671.
What you might notice
Sources
A code explains what the controller detected, not a confirmed root cause.