BoilerFaultCodesVokera E 30 Fault Code
Also written as E30 — same fault.
The Vokera E 30 fault code means: your boiler has detected that the water is heating up or circulating much faster than it should be, causing the system to shut down for safety.. It appears on 1 Vokera model in our database.
Technical description: Temperature differential exceeded
What causes the Vokera E 30 fault?
This fault occurs when the internal sensors detect that the temperature of the water is rising much faster than the boiler can safely handle. It is usually caused by a blockage in the pipework, a build-up of sludge, or a pump that has failed and is no longer pushing water around your radiators. Essentially, the heat being generated has nowhere to go, so the boiler shuts down to prevent internal damage.
This issue often surfaces in autumn when the heating is turned back on for the first time, as internal pump parts can seize up after sitting idle over the summer.
DIY fix possible
Check that your system pressure is between 1.0 and 1.5 bar on the pressure gauge.Ensure all radiator valves are fully open to allow water to circulate.Restart the boiler using the reset button/dial to see if the fault clears.
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Gas Safe Register →Vokera models that show the E 30 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera E 30 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