BoilerFaultCodesWhat the manual says
Manufacturer manualRelay test was activated
From this model's manual
Verified against the Worcester Bosch Greenstar 8000 Life Style installation & service manual, page 76.
What causes this fault?
This occurs when the boiler performs an automated health check on the internal relays that control electrical components. It is a standard safety procedure designed to ensure that the switches on the main circuit board are opening and closing correctly. The boiler pauses briefly during this cycle and typically resumes normal operation once the test is complete.
DIY fix possible
Wait for 5-10 minutes for the automated test sequence to completeIf the code persists, press the 'Reset' button on the front display panel onceEnsure there is power to the boiler and no recent power cuts have occurred
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