BoilerFaultCodesBaxi L7 Fault Code
The Baxi L7 fault code means: your boiler has detected that it is running without enough water inside, which prevents it from operating safely to protect the system from overheating.. It appears on 1 Baxi model in our database.
Technical description: Dry Fire Fault
DIY fix possible
Locate the external filling loop, usually two braided hoses connected to the pipework under the boiler.Open the filling valve slowly until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close the valve tightly to prevent the system from over-pressurising.
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Baxi models that show the L7 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi L7 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