Low
P11 on Vaillant Thermocompact

Your boiler is currently performing a factory calibration check to ensure the gas and air balance is set correctly for your home's fuel supply.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Mid setting point for natural gas (G20)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

P12View →P13View →

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