Low
1-A1 on Worcester Bosch Greenstar 8000 Life Combi

Your boiler is currently stuck in a temporary startup phase and is waiting for everything to be ready before it begins heating.

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

Current status: Status code.

Shared across the Greenstar 8000 Life range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This code appears when the boiler is performing its internal self-checks and preparing its components before officially starting a heating cycle. It is a normal part of the startup sequence and usually indicates the system is simply waiting for a sensor or fan to reach the correct operating state. If the code stays on the screen, it typically means the control board is waiting for a signal that isn't arriving.

DIY fix possible

Wait 15 minutes to see if the boiler clears the code automaticallyEnsure your thermostat is calling for heat or hot waterRestart the boiler using the power button if the code persists for more than 30 minutes

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Related fault codes

All 151 fault codes on the Greenstar 8000 Life Combi

Seeing a different code? Every code this model can display, in one place.

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