Likely causes
- Faulty return thermistor
- Wiring or plug fault
- PCB fault
What you can safely check
- Reset the boiler once; if the code comes straight back, call us
What our engineer does
We test the return sensor and its wiring and replace the faulty part. Anything involving the gas supply, gas valve, combustion chamber, flue, fan, PCB or heat exchanger must be left to a Gas Safe registered engineer and must not be attempted by the householder.
Models this applies to: Baxi 600, Baxi 800, Baxi Platinum, Baxi EcoBlue, Baxi Duo-tec.
Other Baxi codes
Guidance only. Fault codes vary by model and firmware; anything involving gas, the flue, the fan, the gas valve, the PCB or the heat exchanger must be done by a Gas Safe registered engineer.

