Thanks ladybirder. From the manual for your boiler:
"• Eco mode is an energy saving feature which disables the Preheat
function. Eco is enabled by default, during the initial appliance start
up and Eco is displayed.
• Preheat mode, the hot water heat exchanger is kept pre-heated to
reduce the time taken to deliver hot water at the tap.
In the Preheat mode, if there has been no demand for hot water for 24
hours the appliance will save energy by suspending Preheat until there is
a demand for hot water. At this time Preheat mode is re-activated.
▶ Press the eco button (approximately 1 second) to manually switch
between eco [1] and preheat [2] modes.
Depending on which mode the appliance is in, pressing the eco
button (approximately 1 second) switches from one mode to the
other."
So, is your boiler in "Eco mode" at the moment?