Low
6-tb on Worcester Bosch Greenstar 2000

Your boiler is currently running a self-diagnostic test to check the burner's performance across its full power range.

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

Burner test: 0...100%.

DIY fix possible

Wait for approximately 15 minutes for the test to complete automaticallyMonitor the display to see if it returns to the normal temperature readingIf the code persists for over an hour, try restarting the boiler using the reset button

Find a Gas Safe engineer
Search the official register →

Related guides you might find useful

Boiler won't turn on — 9-step checklist

Work through these before the call-out.

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 →