Low
203 on Worcester Bosch Greenstar 4000 GR4700iW 25 C

Your boiler is working correctly and is simply waiting for a signal from your thermostat or timer to start heating.

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

Boiler in standby, no heat energy demand

From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Greenstar 4000 Combi 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 that your room thermostat is turned up higher than the current room temperature.Ensure your heating programmer or app is set to an 'On' period.Check if your wireless thermostat has run out of batteries.

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Related fault codes

202View →204View →

All 92 fault codes on the Greenstar 4000 GR4700iW 25 C

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

2002012022042082142242272282322332342352372382422452492502512522532542582592622632652682692732812832843053063533573583603623631010101310171018101910211023103710651068107010711072107310741075107620852908291029142915291629202923292729282931294029462948294929502951295229572961 V2962 V2963 B2964 B2965 B2966 B2967 B2968 O2969 –2970 B2971 B2972 V3071 –

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