CC 800 Low

Worcester Bosch CC 800 Fault Code

Also written as CC800 — same fault.

The Worcester Bosch CC 800 fault code means: your boiler has lost communication with the outdoor temperature sensor, which means the system cannot automatically adjust its efficiency based on the weather outside.. It appears on 4 Worcester Bosch models in our database.

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
Typical repair cost £90-180 (including labour)

Engineer required

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

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Worcester Bosch models that show the CC 800 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch CC 800 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026