Emergency Lockout
F.62 on Vaillant ecoTEC

Your boiler has detected a potential safety issue where the gas valve is not closing properly or the control board is misreading the gas flow.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description

Gas valve shutoff delay | Gas valve leaking, electronics defective

What causes this fault?

This fault occurs when the boiler's control board detects that gas is still present even after it has commanded the gas valve to close. The most common cause is a physical internal leak in the gas valve itself or a communication error on the main circuit board that prevents it from shutting off the fuel supply correctly.

Engineer required

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

Find a Gas Safe engineer
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Related fault codes

F.61View →F.27View →F.63View →

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