2 pulses No light Low

Worcester Bosch 2 pulses No light Fault Code

Also written as 2PULSESNOLIGHT — same fault.

The Worcester Bosch 2 pulses No light fault code means: your boiler is currently in a manual testing mode used by engineers rather than broken, which is why it has stopped heating your home or water as usual.. It appears on 7 Worcester Bosch models in our database.

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: Not a fault code Service mode selected to min, press service button to return to normal.

What causes the Worcester Bosch 2 pulses No light fault?

This occurs when the service button has been pressed or held, accidentally putting the boiler into its manual 'Minimum' testing mode. It is not caused by a mechanical failure, but rather the internal software waiting for an engineer to finish checking the system. Because it is stuck at a low output, it might seem like the boiler is underperforming or ignoring your thermostat.

DIY fix possible

Locate the service button on the boiler control panel.Press the service button once to exit the current mode.Wait a few moments for the boiler to return to its standard operation status.

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Worcester Bosch models that show the 2 pulses No light fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch 2 pulses No light fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026