Heat pumps · Error codes · Ariston
902Ariston · NIMBUS NET R32 control platform (shared error list)
902 on an Ariston NIMBUS NET R32 control platform: System flow sensor damaged
Short answer
On an Ariston heat pump, 902 means: System flow sensor damaged. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: System flow sensor damaged.
Part involved: system flow temperature sensor.
Likely causes:
- Delivery (flow) sensor not connected or defective.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
What you can check
- Note the error code shown on the Sensys HD interface and contact the installer / Ariston service.
What the engineer will check
- Check the flow sensor connection and replace if necessary.
Who to ask for: heat pump controls / hydronics.
Certification: Competent heating engineer; electrical competence for wiring checks.
What you might notice
Sources
- NIMBUS PLUS M NET R32 - Technical instructions for installation and maintenance (UK) - codes 3301719 3301720, doc 420000656201 EN ↗ · 420011311701 - 03/2024 · page 71 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026