Low
815 on Worcester Bosch Greenstar 8000+ GR8701iW 30 S

Your boiler has detected an issue with a temperature sensor, which may have been accidentally turned on in the settings or affected by moisture.

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.

What the manual says

Manufacturer manual

Low loss header temp. sensor faulty: Tip: Check menu has not been accidentally switched on. Moisture on the connectors – PCB fault.

From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Wb 47115 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check the boiler control menu to see if the low loss header setting was accidentally enabled.Restart your boiler to clear temporary system glitches.If the error persists, contact a heating engineer to check the sensor and wiring for moisture.

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Related fault codes

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All 103 fault codes on the Greenstar 8000+ GR8701iW 30 S

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

2002012022032042082142242272282292322332342352372382422442452462472482492502512522532542572582592622632652682692732812832843053063573583603623636048111010101310171018101910221023102510371065106810701071107210751076208529082910291429152916292029232924292529262927292829312940294629482949295029512952295529562957296129622963296529662968296929702971297229802981

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