Low
800 on Worcester Bosch Greenstar 28CDi

Your boiler is having trouble communicating with the temperature sensor located outside your home, which may cause your heating to run less efficiently.

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.

What the manual says

Manufacturer manual

CC Outdoor sensor defect

From this model's manual
Verified against the Worcester Bosch Greenstar 28cdi Compact installation & service manual, page 66.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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