High
70 on Alpha E-Tec Plus 24

Your boiler is struggling to detect water temperature correctly, which is likely caused by a blocked system, loose wiring, or a faulty sensor prevented it from heating properly.

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

Possible wiring fault, sensors incorrectly fitted, system blocked

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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