BoilerFaultCodesBaxi 135 Fault Code
The Baxi 135 fault code means: your boiler has stopped working because it has detected an issue with the internal gas valve or the way it is communicating with the gas supply.. It appears on 10 Baxi models in our database.
Technical description: Interruption Of Gas Supply (Internal Error)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Baxi models that show the 135 fault code
Click a model for the full fault code list and model-specific repair notes.
- 124 Combi Repair: £120-350
- 600 Combi (range) Repair: £150-380
- 624 Combi Repair: £150-£350
- 825 Combi Repair: £280-450
- Assure Repair: £120-250
- Combi 105 HE Repair: £150-250
- Combi Instant 80/105 HE Repair: £120-250
- Duo-tec Combi GA Repair: £150-£350
- Duo-tec Combi HE A Repair: £150-300
- Eco Compact Repair: £120-250
Source
Baxi 135 fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026