Low Information
1-C4 on Worcester Bosch Greenstar 8000 Life/Style

Your boiler is displaying the current outdoor temperature because an external weather sensor is connected, which is a normal status reading rather than a breakdown.

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

Outside temperature: Current outside temperature (with outside temperature sensor connected)

What causes this fault?

This code appears because your heating system has an optional weather compensation sensor installed on the outside of your property. It acts as an information display rather than a mechanical failure, simply showing the boiler's reading of the current air temperature. This allows the boiler to automatically adjust its efficiency based on how cold it is outside.

DIY fix possible

Check if the display returns to the normal temperature screen automaticallyPress the 'Back' or 'Reset' button once to clear the informational messageEnsure the external sensor is not obstructed by snow or debris

Find a Gas Safe engineer
Search the official register →

Related guides you might find useful

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →