BoilerFaultCodesBaxi E20 Fault Code
The Baxi E20 fault code means: your boiler's internal temperature sensor has stopped communicating correctly, preventing the system from heating your radiators.. It appears on 9 Baxi models in our database.
Technical description: Central heating NTC error
What causes the Baxi E20 fault?
This fault occurs when the boiler's control board loses communication with the temperature sensor responsible for your radiators. This is typically caused by the internal sensor failing due to age or a loose electrical connection in the wiring harness that prevents the boiler from monitoring how hot the water is.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Baxi models that show the E20 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi E20 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