BoilerFaultCodesThe 6 most common faults
01
04 High DIY-safe
Your boiler has stopped working because the water pressure inside the system has dropped too low.
What to try first
Locate the external filling loop, usually a silver braided hose under the boiler.Open the small valve(s) at either end to allow water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Ensure both valves are fully closed tightly and reset the boiler.
02
02 High Engineer
Your boiler is failing to circulate water properly because it cannot sense the flow it needs to heat your home.
Full guide for 0203
06 High Engineer
Your boiler has detected an internal configuration error with its main electronic brain, which prevents it from operating safely.
Full guide for 0604
07 High Engineer
Your boiler has stopped working because it is unable to accurately measure the temperature of the water inside the unit.
Full guide for 0705
08 High Engineer
Your boiler has detected that it is running too hot and has automatically shut down to prevent damage to its internal components.
Full guide for 0806
09 High Engineer
Your boiler's internal computer has developed an error and can no longer control the heating system correctly.
Full guide for 09on the Vokera Synergy
Filling loopPressure relief valveExpansion vesselCirculating pumpFlow sensorIsolation valves
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 Vokera 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