Ariston Nimbus Fault Codes
The Ariston Nimbus is the brand's air-source heat pump range — Nimbus Pocket, Compact and Flex configurations pairing an outdoor unit with hydraulic modules indoors, controlled through Ariston's Sensys HD interface and Ariston NET connectivity. It represents Ariston's push into the UK heat pump market alongside its boiler stable, and it reports faults through the Sensys display and app as error codes with descriptive text. A heat pump's fault landscape differs from a boiler's: no gas or flame codes, but refrigerant-circuit protections, water-flow and pump faults, sensor errors across both units, defrost-related conditions in winter, and communication faults between indoor and outdoor units. Work on the sealed refrigerant circuit legally requires an F-Gas registered engineer — for anything beyond checking water pressure and the outdoor unit's airflow, the right call is your installer or an Ariston-accredited heat pump engineer, with Ariston NET remote diagnostics often shortening the visit.
Where Nimbus fault codes appear
Faults show on the Sensys HD controller indoors — code plus description — and mirror to the Ariston NET app on connected installations. Photograph the controller screen or the app entry; the code with its text is what Ariston support and engineers work from.
Resetting a Ariston Nimbus
The Sensys controller offers reset/acknowledge for clearable faults; heating-water pressure top-ups follow the same 1–1.5 bar logic as any sealed system. Outdoor-unit conditions — icing, airflow blockages — are worth a visual check, but leave the unit's covers closed. Persistent or returning faults belong with an F-Gas qualified engineer, not repeated resets.
Common Nimbus problems
Real-world Nimbus issues cluster where all air-source installations do: water-flow faults from filters and system debris, winter defrost-related conditions where drainage or airflow is compromised, sensor and communication errors between modules, and configuration issues in early-life installs. The range is young and warrantied — registration, annual servicing and the connected diagnostics are the ownership essentials.
Most common Nimbus fault codes
- 5P1 The 5P1 code appears on Ariston boilers when the burner fails to ignite on the first… Read more →
- 304 Ariston fault code 304 is a safety lockout triggered when the boiler has been reset too… Read more →
- 607 Fault code 607 on an Ariston boiler means the air pressure switch has registered a closed… Read more →
- 301 Fault code 301 on an Ariston boiler signals a problem with the EEPROM — the small memory… Read more →
- 107 Fault code 107 on Ariston boilers signals an 'Insufficient Circulation' condition. The… Read more →
- 209 Ariston fault code 209 is a safety lockout triggered when the boiler's processor detects… Read more →
- 114 Fault code 114 on Ariston boilers signals a problem with the external (outdoor)… Read more →
- 116 Ariston fault code 116 points to a problem with the room temperature sensor circuit or,… Read more →
- 412 Ariston fault code 412 belongs to the '4' functional group, which covers communication,… Read more →
- 502 Ariston fault code 502 indicates that the boiler's flame detection system is registering… Read more →