High Lockout
E 33 on Vokera Hydra

Your boiler has detected an electrical fault with one of its temperature sensors, meaning it cannot accurately read the heat levels and will stop working to keep you safe.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Short circuit on inlet sensor

What causes this fault?

This fault occurs when the electrical sensor responsible for measuring the temperature of water entering your boiler fails or suffers a short circuit. The most common reason is that the sensor's internal components have worn out over time, leading to an incorrect electrical signal that prevents the boiler from firing safely.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E 32View →

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