How much does it cost to fix Baxi error code E28?

Typical repair cost for the Baxi E28 fault is £100-£180 including labour.

E28 High

Baxi E28 Fault Code

Q: What does the Baxi E28 fault code mean?

Your boiler has detected a problem with the internal sensor that monitors the temperature of the exhaust gases, causing the system to shut down for safety.

The Baxi E28 fault code means: your boiler has detected a problem with the internal sensor that monitors the temperature of the exhaust gases, causing the system to shut down for safety.. It appears on 37 Baxi models in our database.

Technical description: Flue negative temperature coefficient (NTC) thermostat fault.

What causes the Baxi E28 fault?

This fault occurs when the boiler's control system receives an incorrect or missing signal from the sensor that monitors exhaust gas temperatures. The most common reason is that the sensor itself has developed an electrical failure or the wiring connecting it to the main control board has become loose or damaged. Because this sensor is a vital safety component that prevents the boiler from overheating internally, the system will shut down immediately to prevent damage.

Typical repair cost £100-£180 (including labour)

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 E28 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Baxi E28 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