BoilerFaultCodesAriston 7 02 Fault Code
Also written as 702 — same fault.
The Ariston 7 02 fault code means: your boiler is having trouble communicating with the temperature sensor for your secondary heating zone, which may prevent that part of your home from heating up properly.. It appears on 13 Ariston models in our database.
Technical description: Zone 2 return sensor defective
What causes the Ariston 7 02 fault?
This fault occurs when the control board loses communication with the sensor monitoring the water temperature for your second heating zone. This is usually caused by the internal sensor failing due to age or a loose electrical connection in the wiring harness between the sensor and the main board.
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 7 02 fault code
Click a model for the full fault code list and model-specific repair notes.
- Challenger 80E Repair: £120-220
- Clas HE 24 Repair: £120-220
- Clas HE 28 Repair: £120-220
- Clas HE 35 Repair: £120-220
- Clas HE Evo Repair: £120-200
- Clas Net One Repair: £120-200
- Clas One Repair: £120-220
- Clas System 28 Repair: £120-200
- E-Combi Evo Repair: £120-220
- E-Combi One Repair: £120-220
- E-Combi One 24 Repair: £100-£180
- E-Combi One 30 Repair: £120-220
- Microsystem 15 Repair: £120-220
Source
Ariston 7 02 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