BoilerFaultCodesThe 6 most common faults
01
E24 High Engineer
Your boiler has detected an issue with the valve that regulates the gas flow, meaning it cannot safely ignite or maintain a flame to heat your home.
Full guide for E2402
E03 High Engineer
Your boiler has detected that it is getting too hot and has automatically switched itself off to prevent any damage or safety issues.
Full guide for E0303
E26 High Engineer
Your boiler has detected that the internal exhaust system is not working correctly, so it has safely shut down to prevent unsafe gases from building up.
Full guide for E2604
Overheat Neon High Engineer
Your boiler has switched itself off because it has detected that it is getting too hot, likely due to a circulation issue.
Full guide for Overheat Neon05
E01 Emergency Engineer
Your boiler has failed to ignite because the internal flame sensor is not detecting a steady burn.
Full guide for E0106
Lockout Medium DIY-safe
Your boiler has automatically turned itself off because it became too hot, acting as a safety measure to prevent damage.
What to try first
Turn the boiler control knob to the OFF position.Wait for at least 10 seconds to allow the internal sensors to reset.Turn the control knob back to the ON position and observe if the boiler fires up normally.
on the Baxi Solo 3 PF
Gas ValveWiring HarnessPCBOverheat ThermostatPumpFan assembly
Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.
Call a Gas Safe engineer if…
- You can smell gas or see signs of a leak
- The Baxi shows an Emergency or High severity code
- The boiler keeps locking out after repeated resets
- You've tried the DIY checks and the fault hasn't cleared
- There's visible water leaking from the boiler
- The flame is yellow or orange instead of blue