104 Low

Worcester Bosch 104 Fault Code

The Worcester Bosch 104 fault code means: your boiler is having trouble communicating with the heat sensor in your solar hot water tank, meaning it may struggle to efficiently use solar energy to heat your water.. It appears on 1 Worcester Bosch model 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: Fault 41 Temperature sensor T2 at bottom of solar cylinder faulty: Break in the sensor lead
Typical repair cost £120-220 (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 104 fault code

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

Source

Worcester Bosch 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 7 July 2026