Low
CC 800 on Worcester Bosch Junior 28i

Your boiler is unable to communicate with its outdoor temperature sensor, meaning it cannot adjust its heating efficiency based on the weather outside.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Outdoor sensor defect available when accessory outdoor sensor is connected

Engineer required

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

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Related fault codes

A7View →E9View →

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