Greenstar 30Si Compact NG condensing boiler Preheat doesn't work

[xomuz]

First of all, I should say that I don't have any knowledge about plumbing or boilers.
I tried to turn on the preheat by holding the Eco button and selecting "On" on the display.
As you can see in the screenshot, PreHeat appears to be on, yet the water still takes a long time to heat up at the tap.
What am I missing here?

It's a Greenstar 30Si Compact NG condensing boiler

 

[cross thread]

Pre heat warms the boiler, if it’s a decent length run of pipe to the tap it wi still take a while , how long is the run and how long does it take ?

 

[xomuz]

Pre heat warms the boiler, if it’s a decent length run of pipe to the tap it wi still take a while , how long is the run and how long does it take ?

The bathroom is on the same floor, a few metres from the boiler. It takes at least a minute for the water to start getting warm