BoilerFaultCodesWorcester Bosch 51133 Fault Code
The Worcester Bosch 51133 fault code means: your boiler has detected a fault with the solar collector temperature sensor, meaning it cannot correctly monitor heat coming from your solar panels.. It appears on 1 Worcester Bosch model in our database.
Technical description: Temperature sensor type PTC 1000 used as collector temperature sensor (T1).
What causes the Worcester Bosch 51133 fault?
This fault occurs when the boiler loses communication with the sensor that monitors the heat of your solar panels. It is usually caused by the sensor itself failing due to long-term exposure to extreme temperatures or a break in the wiring connecting the panels to the boiler. As a result, the system cannot safely determine if there is enough solar energy available to heat your water.
This fault is more common during the summer months when solar collectors reach their highest temperatures, which can stress or perish aging sensors.
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 51133 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 51133 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