High Lockout
Yellow | On permanently on Vokera Compact HE

Your boiler has detected a problem with the hot water system, meaning you likely have no hot water even if your heating still works.

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

DHW fault

What causes this fault?

This fault occurs when the boiler's internal computer receives an incorrect or missing signal from the temperature sensors responsible for your hot water. The most common reason is that the domestic hot water sensor has failed or become corroded, preventing the boiler from knowing how hot the water is and causing it to shut down the hot water function as a safety precaution.

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

Red | On permanentlyView →

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