BoilerFaultCodesWorcester Bosch 224 V Fault Code
Also written as 224V — same fault.
The Worcester Bosch 224 V fault code means: your boiler has switched itself off because it has detected it is getting too hot, usually caused by the water pressure being too low.. It appears on 10 Worcester Bosch models in our database.
Technical description: Safety temperature limiter has tripped – top-up water until the reset pressure is reached
What causes the Worcester Bosch 224 V fault?
This fault occurs when the internal safety sensor detects that the heat exchanger has become dangerously hot, causing the boiler to shut down to prevent damage. The most common reason is a lack of water circulating through the system, often due to low pressure, a blockage, or a pump failure. If there isn't enough water to carry the heat away to your radiators, the temperature inside the unit rises too quickly.
This issue often surfaces when the heating is first turned on in autumn, as pump components can seize or air locks can develop after being idle during the summer.
DIY fix possible
Check the pressure gauge on the front of the boiler or the digital display.Locate the filling link (usually a blue lever underneath the boiler or a white plastic key).Slowly top up the water pressure until it reaches between 1.0 and 1.5 bar.Press the 'Reset' button on the boiler display to clear the fault.
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Gas Safe Register →Worcester Bosch models that show the 224 V fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 224 V 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 27 April 2026