BoilerFaultCodesBaxi E28 Fault Code
The Baxi E28 fault code means: your boiler has detected a problem safely discharging exhaust gases or removing waste water, causing it to shut down for safety.. It appears on 12 Baxi models in our database.
Technical description: Error with the NTC (Negative Temperature Coefficient) flue, air pressure switch or blocked flue or condensate
What causes the Baxi E28 fault?
This fault occurs when the boiler's internal safety sensors detect that the exhaust gases are too hot or cannot escape the property correctly. It is often triggered by a breakdown in the sensor that monitors flue temperatures, or a physical blockage in the pipe that carries waste water away from the unit. When the system can no longer safely vent heat or clear condensation, it shuts down to prevent internal damage.
This fault is significantly more common during freezing winter temperatures, as the external condensate drainage pipe can freeze solid and cause a backup into the boiler.
DIY fix possible
Check the external plastic condensate pipe for signs of freezing or blockageGently pour warm water over the external pipe if it is frozenEnsure the external flue terminal on your wall is not obstructed by debris or plantsReset the boiler once by turning the selector knob to 'R' for five seconds
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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.
- Assure Repair: £0-120
- Duo-tec Combi ErP Repair: £120-250
- Duo-tec Combi HE Repair: £150-250
- Duo-tec Combi HE A Repair: £150-250
- Megaflo System Repair: £150-300
- Platinum 24 Combi ErP Repair: £120-250
- Platinum 28 Combi ErP Repair: £120-£220
- Platinum Combi HE Repair: £90-180
- Platinum Combi HE (2007) Repair: £100-£200
- Platinum Combi HE A Repair: £150-250
- Platinum Heat Repair: £100-280
- Platinum+ 40 Combi Repair: £120-250
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 31 August 2026