BoilerFaultCodesBiasi L01 Fault Code
The Biasi L01 fault code means: your boiler has detected that the water inside the unit is getting too hot while it is trying to heat your tap water, so it has shut down to prevent damage.. It appears on 3 Biasi models in our database.
Technical description: Primary circuit temp. limit during D.h.w. operation
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Biasi models that show the L01 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Biasi L01 fault code information on this page is sourced and cross-checked against the official Biasi service / installation manuals for each affected model.
- Biasi Activ A manual (PDF)
- Biasi Advance Plus 16S 25S 30S manual (PDF)
- Biasi Rinnova Adaptive Combi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026