Low Information
C4273 on Worcester Bosch GB162

Your boiler is performing a routine safety self-check and will restart automatically in a few minutes.

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

The boiler was switched off for a maximum of 2 minutes because it had been operating continuously for more than 24 hours

What causes this fault?

This occurs because the boiler is programmed to perform a safety self-test after running for twenty-four hours straight without a break. To complete this check, the system briefly pauses the burner to ensure all internal safety sensors are functioning correctly. It is a built-in software feature rather than a mechanical failure or a broken part.

This code is more common during the winter months when the heating is left on constantly to combat freezing external temperatures.

DIY fix possible

Wait for 2 minutes for the boiler to complete its safety cycleMonitor the display to ensure the code clears and the boiler restarts automaticallyIf the code persists for more than 10 minutes, try a manual reset

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