BoilerFaultCodesAriston 3 01 Fault Code
Also written as 301 — same fault.
The Ariston 3 01 fault code means: your boiler's main internal computer has developed a fault and is unable to communicate with the rest of the system, meaning the boiler will not function.. It appears on 14 Ariston models in our database.
Technical description: Internal P.C.B. error
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 3 01 fault code
Click a model for the full fault code list and model-specific repair notes.
- Challenger 80E Repair: £250-400
- Clas HE 24 Repair: £250-450
- Clas HE 28 Repair: £250-450
- Clas HE 35 Repair: £250-450
- Clas HE Evo Repair: £250-450
- Clas Net One Repair: £200-400
- Clas One Repair: £150-300
- Clas System 28 Repair: £200-400
- E-Combi Evo Repair: £250-450
- E-Combi One Repair: £250-400
- E-Combi One 24 Repair: £220-400
- E-Combi One 30 Repair: £250-400
- Egis Repair: £150-300
- Microsystem 15 Repair: £250-400
Source
Ariston 3 01 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