Medium Warning
1-d3 on Worcester Bosch Greenstar 8000 Life/Style

Your boiler is reporting an issue with the pump that circulates fluid between your solar panels and the water tank.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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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

Collector pump: Is only displayed, if a solar module is connected.

What causes this fault?

This fault occurs when the system detects that the pump responsible for moving heated fluid from your solar panels to your hot water tank is not functioning correctly. The most common reasons are a mechanical failure within the solar pump itself, a faulty sensor failing to read the fluid temperature, or a communication error between the solar control module and the boiler.

This fault is more common during the summer months when high levels of solar radiation put the pump and sensors under maximum operating demand.

Engineer required

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

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