Low Information
T1 on Worcester Bosch Greenstar Si Combi / i System

Your boiler is currently running a self-diagnostic check to ensure the ignition system is sparking correctly before it starts up.

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

Ignition test – checking the igniter spark

What causes this fault?

This is a brief, automated check that occurs when the boiler prepares to light the burner. It happens because the system's control board needs to verify that the ignition electrodes are capable of creating a spark before releasing gas. It is not an indication of a breakdown, but rather a standard safety protocol being carried out by the internal computer.

DIY fix possible

Wait for the test to complete automaticallyIf the code stays on screen for more than a few minutes, try restarting the boiler via the Reset button

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