BoilerFaultCodesVokera E35 Fault Code
The Vokera E35 fault code means: your boiler has stopped working because the internal water pressure is too low for the system to run safely.. It appears on 1 Vokera model in our database.
Technical description: Water pressure switch error – contact not closed
What causes the Vokera E35 fault?
This fault occurs when the boiler detects that there isn't enough water pressure inside the system to operate safely. The most common reason is a slow leak somewhere in your radiators or pipework, but it can also happen if the expansion vessel has lost its air charge and can no longer regulate pressure correctly.
This issue often appears when you first turn the heating back on in autumn, as small leaks or air pockets that developed over summer become apparent once the system is under load.
DIY fix possible
Check the pressure gauge on the front of the boiler or under the casing.If the needle is below 1.0 bar, locate the filling loop (flexible silver hose).Slowly open the valves to top up the water until the pressure reaches 1.5 bar, then close them tightly.
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Gas Safe Register →Vokera models that show the E35 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera E35 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