BoilerFaultCodesWorcester Bosch Fault 20 / 193 Fault Code
Also written as FAULT20193 — same fault.
The Worcester Bosch Fault 20 / 193 fault code means: your boiler's computer and its remote control are having trouble speaking the same language, causing the system to stop working correctly.. It appears on 1 Worcester Bosch model in our database.
Technical description: System configuration: invalid. Invalid coding in remote control for the heating circuit.
What causes the Worcester Bosch Fault 20 / 193 fault?
This fault occurs when the boiler's internal computer receives conflicting information about how it should be operating. The most common reason is that a newly installed part or external thermostat hasn't been programmed correctly to talk to the boiler, or an electrical glitch has corrupted the system's memory. It essentially means the boiler has forgotten its own identity and shuts down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Worcester Bosch models that show the Fault 20 / 193 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch Fault 20 / 193 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