High
27 on Alpha E-Tec R

Your boiler has detected that the water inside it is heating up much faster than normal, which suggests a blockage or lack of water flow preventing the system from cooling down.

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

Rapid temperature rise of primary sensor

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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