BoilerFaultCodesBaxi H.01.08 Fault Code
Also written as H0108 — same fault.
The Baxi H.01.08 fault code means: your boiler is heating up too quickly and has temporarily shut down to prevent overheating, usually because the water cannot circulate properly through your radiators.. It appears on 8 Baxi models in our database.
Technical description: Flow temperature rise in heating mode too quick (10-min stop)
DIY fix possible
Check that your boiler pressure is between 1 and 1.5 bar on the gauge.Ensure at least two or three radiators have their valves fully open.Bleed your radiators to remove any trapped air that might be blocking water flow.
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Baxi models that show the H.01.08 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi H.01.08 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