203 0 Low

Worcester Bosch 203 0 Fault Code

Also written as 2030 — same fault.

The Worcester Bosch 203 0 fault code means: your boiler is working correctly but is currently resting because it hasn't been told to turn on by your thermostat or timer.. It appears on 3 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: Boiler in standby – no heat energy demand

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 'On' or 'Auto'.Replace the batteries in your wireless thermostat if the screen is blank.

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Avoid the next call-out bill

A cover plan would handle faults like 203 0: no call-out fees, no surprise bills.

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Worcester Bosch models that show the 203 0 fault code

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

Source

Worcester Bosch 203 0 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 7 July 2026