Low
D.24 on Vaillant Turbomax Plus 824/828E

Your boiler is currently performing a diagnostic check on its external controls, such as your room thermostat or timer, to ensure they are communicating correctly.

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

Diagnostic code check (page 52) / External controls check

Engineer required

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

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Related fault codes

F.24View →

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