Medium
Er.15 on Vaillant Turbomax Pro 28 2E

Your boiler is struggling to detect when you turn on a hot tap, which means you may have no hot water or the water temperature might stay cold.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Aqua sensor

Engineer required

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

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