Low
S.98 on Vaillant Atmomax

Your boiler is temporarily paused because it has detected a mismatch between the temperature sensors and needs to double-check them before starting up.

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

Flow return sensor check is running demand is block

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.22View →F.23View →F.24View →

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