BoilerFaultCodesBaxi 27 Fault Code
The Baxi 27 fault code means: your boiler has stopped working because it either doesn't have enough water inside the system to operate safely or the internal water pump is failing to move the water around.. It appears on 8 Baxi models in our database.
Technical description: Fault on Pump or Low System Pressure
DIY fix possible
Check your boiler's pressure gauge on the front panel; if it is below 1.0 bar, use the filling loop to top the system up to between 1.0 and 1.5 barEnsure your central heating system does not have any obvious water leaks coming from radiators or the boiler itselfOnce pressure is restored, reset the boiler using the reset button on the control panel
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Baxi models that show the 27 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi 27 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