Low
P4 on Worcester Bosch Greenstar R29 40 HE

Your boiler is currently performing a standard internal start-up check to ensure all its systems are safe and ready to operate.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Part of the self-test sequence sequence when the appliance is switched on.

DIY fix possible

Wait for 5 minutes to allow the boiler self-test to complete.If the code persists, perform a soft reset by pressing the reset button on the boiler interface.Power cycle the boiler by switching it off at the wall or spur, waiting 30 seconds, and switching it back on.

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