BoilerFaultCodesBaxi 110 Fault Code
The Baxi 110 fault code means: your boiler has detected that it is overheating and has shut itself down to prevent damage because it cannot circulate water properly.. It appears on 25 Baxi models in our database.
Technical description: Safety Thermostat operated or faulty - Flow & Return Sensors check (Section H/D)
What causes the Baxi 110 fault?
This fault occurs when the water inside your boiler becomes too hot, causing a safety sensor to trip and shut the system down to prevent damage. The most common reason is that the water cannot move around the system properly, often due to an airlock in the pipework or a pump that has failed. It can also happen if your radiator valves are all closed or if there is a physical blockage restricting the flow.
This fault is frequently seen in autumn when heating systems are turned back on after a long summer break, as pump components can seize up from lack of use.
DIY fix possible
Turn off the boiler and allow it to cool down completely.Use a radiator key to bleed all radiators to remove any trapped air.Check the boiler pressure gauge and top it up to 1.5 bar if it has dropped.Turn the boiler back on and press the 'Reset' button.
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Baxi models that show the 110 fault code
Click a model for the full fault code list and model-specific repair notes.
- 100/2 HE Plus Repair: £100-280
- 124 Combi Repair: £180-£350
- 200 / 400 Combi Repair: £150-300
- 600 Combi (range) Repair: £120-280
- 624 Combi Repair: £100-280
- 630 COMBI LPG
- 636 COMBI
- 636 COMBI LPG
- 818 System Repair: £100-280
- 825 Combi Repair: £90-250
- Assure Repair: £150-300
- Duo-tec Combi ErP Repair: £120-220
- Duo-tec Combi GA Repair: £90-180
- Duo-tec Combi HE A Repair: £150-£300
- EcoBlue Repair: £150-300
- Ecoblue 12 System ErP
- Ecoblue 15 System ErP
- Ecoblue 24 System ErP
- Ecoblue 28 System ErP
- Ecoblue Advance Combi Repair: £150-300
- EcoBlue System Repair: £180-350
- PLATINUM COMPACT 25 COMBI
- PLATINUM COMPACT 30 COMBI
- PLATINUM COMPACT 36 COMBI
- Suprima 100 Repair: £100-280
Source
Baxi 110 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 31 August 2026