Low
S.98 on Vaillant ecoTEC plus System

Your boiler is currently running a self-diagnostic check, which is temporarily pausing your heating and hot water.

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

Automatic test programme: Return temperature sensor, heating and hot water request blocked.

Engineer required

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

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Related fault codes

S.96View →S.97View →F.22View →

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