Low
203 on Worcester Bosch Greenstar 1000

Your boiler is perfectly healthy and simply waiting for a signal from your thermostat to turn on the heating or hot water.

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 1000 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.

What causes this fault?

Status code - normal operation

DIY fix possible

Turn up your room thermostat or smart controller settingsCheck that your hot water timer or programmer is set to 'On'Wait for a few minutes to see if the boiler fires up once a heat request is sent

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