BoilerFaultCodesVokera Test4 Fault Code
Also written as TEST4 — same fault.
The Vokera Test4 fault code means: your boiler has failed to light the flame after several attempts, meaning it cannot provide you with any heating or hot water.. It appears on 1 Vokera model in our database.
Technical description: Ignition fault
What causes the Vokera Test4 fault?
This fault occurs when the boiler's control system attempts to light the burner but fails to detect a stable flame after several tries. It is often caused by a lack of spark, a problem with the gas supply, or dirty components that prevent the boiler from sensing that a fire has successfully started.
This fault is slightly more common in winter when increased demand can highlight underlying issues with gas pressure or when moisture buildup affects the electrical ignition components.
DIY fix possible
Check that your gas prepayment meter has credit (if applicable)Check that other gas appliances in your home, like a hob, are working correctlyPress the 'Reset' button on the boiler control panel to see if it clears the lockout
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Vokera models that show the Test4 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera Test4 fault code information on this page is sourced and cross-checked against the official Vokera service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026