High
A05 on Ariston Euro Prisma 24

Your boiler is struggling to switch between providing heating and hot water because an internal mechanical valve has become stuck or failed.

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

Motorised Valve

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

A03View →A04View →E05View →

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