High
D.30 on Vaillant Atmomax

Your boiler's main control board is currently unable to communicate with the gas valves that provide fuel for the flame.

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

Control signal for both gas valves

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

F.26View →D.33View →F.62View →

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