High
C1 on Alpha Cd13r

Your boiler has stopped working because it is unable to accurately measure the temperature of the water returning to it, so it has shut down as a precaution.

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

Primary return temperature sensor faulty (no heating); cold resistance approx. 12-14 kohms

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

C2View →

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