BoilerFaultCodesVokera Pressure fall below 0.5 BAR Fault Code
Also written as PRESSUREFALLBELOW05BAR — same fault.
The Vokera Pressure fall below 0.5 BAR fault code means: your boiler has detected that the water pressure is too low to operate safely and has switched itself off to prevent damage.. It appears on 2 Vokera models in our database.
Technical description: The boiler shuts off automatically. The minimum permissible level for the safe and efficient operation of the appliance is 0.5 BAR.
What causes the Vokera Pressure fall below 0.5 BAR fault?
This fault occurs when the water volume inside your central heating system drops below a safe operating level, often due to a small leak in the pipework or a radiator. It can also happen if your radiators were recently bled without the system being topped up, or if an internal component like the expansion vessel is no longer holding pressure correctly. When the pressure drops too low, the boiler shuts down to prevent the internal heat exchanger from overheating and sustaining permanent damage.
This issue is more common at the start of autumn when homeowners turn their heating back on after a long summer break, often revealing small leaks that developed while the system was idle.
DIY fix possible
Locate the external filling loop (the flexible silver hose) under or near the boiler.Slowly open the one or two taps on the hose until you hear water entering.Watch the pressure gauge and close the taps once the needle reaches between 1 and 1.5 bar.
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Gas Safe Register →Vokera models that show the Pressure fall below 0.5 BAR fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera Pressure fall below 0.5 BAR 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