Fault 41 104 Medium

Worcester Bosch Fault 41 104 Fault Code

Also written as FAULT41104 — same fault.

The Worcester Bosch Fault 41 104 fault code means: your boiler is struggling to read the temperature of the water in your solar cylinder due to a broken or faulty sensor or connection.. It appears on 2 Worcester Bosch models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Break in the sensor lead (T2). Temperature sensor T2 at bottom of solar cylinder faulty.

What causes the Worcester Bosch Fault 41 104 fault?

This fault occurs when the boiler loses communication with the sensor responsible for monitoring the temperature in your solar hot water tank. It is usually caused by a physical break in the sensor's wiring or internal failure of the temperature probe itself, meaning the boiler can no longer safely manage the solar heating process.

This issue may become more apparent during the summer months when solar thermal systems are most active and the sensor is under constant use.

Typical repair cost £90-180 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Worcester Bosch models that show the Fault 41 104 fault code

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

Source

Worcester Bosch Fault 41 104 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