BoilerFaultCodesAriston 1 P3 Fault Code
Also written as 1P3 — same fault.
The Ariston 1 P3 fault code means: your boiler has detected that water is not flowing around your heating system as efficiently as it should, possibly due to a blockage or a pump issue.. It appears on 14 Ariston models in our database.
Technical description: Insuffi cient circulation indication
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Ariston models that show the 1 P3 fault code
Click a model for the full fault code list and model-specific repair notes.
- Challenger 80E Repair: £150-300
- Clas HE 24 Repair: £120-250
- Clas HE 28 Repair: £120-250
- Clas HE 35 Repair: £120-250
- Clas HE Evo Repair: £120-250
- Clas Net One Repair: £120-250
- Clas One Repair: £90-250
- Clas System 28 Repair: £150-350
- E-Combi Evo Repair: £120-250
- E-Combi One Repair: £150-300
- E-Combi One 24 Repair: £120-£350
- E-Combi One 30 Repair: £150-300
- Egis Repair: £120-250
- Microsystem 15 Repair: £150-300
Source
Ariston 1 P3 fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026