BoilerFaultCodesBaxi E85 Fault Code
The Baxi E85 fault code means: your boiler's internal computer has lost contact with its sensors or other parts, meaning it cannot receive the signals it needs to operate safely.. It appears on 1 Baxi model in our database.
Technical description: No communication.
What causes the Baxi E85 fault?
This fault occurs when the boiler's main control board loses its ability to 'talk' to the internal sensors or the display screen. The most common reason is a loose connection or a degraded wire within the internal harness, though it can also be caused by the electronic control board failing entirely. Because the boiler can no longer monitor its own safety sensors, it shuts down immediately to prevent damage.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Baxi models that show the E85 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi E85 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 27 April 2026