BoilerFaultCodesYour boiler has been accidentally put into a testing mode and simply needs to be switched back to its normal operating setting.
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: Not a fault code - Service mode selected to max, press service button to return to normal
What causes this fault?
This occurs when the service button has been pressed or held, which tells the boiler to run at its maximum power for testing purposes. It is not a mechanical failure, but rather a specific manual setting used by engineers that has been left active. The boiler stops following your thermostat's instructions because it is prioritising this internal diagnostic mode.
DIY fix possible
Locate the button with a 'spanner' or 'service' icon on the front control panel.Press and release the service button once.The flashing blue light should stop and stay solid, indicating the boiler is back in normal mode.
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A boiler cover plan would cover faults like 5 pulses / No light — no call-out fees, no surprises.
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Worcester Bosch Greenstar 24i Junior is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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