BoilerFaultCodesThe 3 most common faults
01
8.2 Diagnostic LED Indicators High Engineer
Your boiler is signalling a specific internal error through its light display, indicating that the system is unable to operate normally and requires investigation to identify the underlying mechanical or electrical fault.
Full guide for 8.2 Diagnostic LED Indicators02
8.3 Faulting Finding Codes High Engineer
Your boiler has detected an internal error that requires a professional manual to identify the specific cause.
Full guide for 8.3 Faulting Finding Codes03
H. Medium Engineer
Your boiler has accidentally entered a testing mode used by engineers, meaning it is currently running at a very low power setting and may not heat your home or water effectively.
Full guide for H.on the Halstead Eden Vbx
Printed Circuit Board (PCB)Temperature sensorsWiring harnessPrinted Circuit BoardControl sensorControl PCB
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 Halstead 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