High
S.53 on Vaillant Home System

Your boiler has temporarily paused operation because it has detected an issue with the water flow, likely caused by low pressure or a blockage in the system.

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

Product in waiting period/operation block function due to low water pressure (flow/return spread too large)

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.22View →F.24View →S.54View →

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