BoilerFaultCodesWhat the manual says
Manufacturer manualControl mode - Solar control unit error message
What causes this fault?
This fault occurs when the boiler's main brain loses its connection with the separate control box that manages your solar thermal panels. The most common reason is a loose or damaged communication cable between the two units, or a component failure within the solar pump station itself. When this happens, the system can no longer tell if the solar panels are providing heat, so it stops relying on them to warm your water.
This issue is often more noticeable during the spring and summer months when high levels of sunshine mean the boiler should be relying heavily on solar power rather than gas.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like 9F: no call-out fees, no surprise bills.
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