Your boiler is currently providing hot water to your taps or shower, which is a normal status message rather than an actual fault.

Hot water demand

What causes this fault?

This status appears when the boiler detects that a hot water tap or shower has been turned on, triggering the internal flow sensor. It indicates that the burner has fired up specifically to heat the water for your domestic use rather than for your central heating. Because this is a normal operational message, it does not mean your boiler has stopped or broken down.