Your boiler has detected a problem with the sensor that measures the water temperature in your solar cylinder, which may affect how your hot water is heated.

Control mode - Solar: Cylinder temperature sensor shorted out

What causes this fault?

This fault occurs when the sensor responsible for monitoring the temperature of your solar water cylinder develops an electrical fault, causing it to send an incorrect signal to the boiler's control board. The most common reason is that the sensor's internal wiring has degraded over time or moisture has caused a short circuit, preventing the system from knowing if the water is hot enough. In some cases, it can also be triggered by a loose or damaged connection in the wiring harness that links the sensor to the main unit.