This timeswitch is from the 'Hive' stable by British Gas, with a similar interface. That's all good news; it is one of the best and most intuitive timers to set up and operate.
The annoying aspect about all these BG and Hive units is the limited information available on them on the 'net; if you can find operating instructions on these items, then well done you; not even BG or Hive themselves have this or are willing to part with it. They won't even tell you what each unit DOES!
As it happens, you'll have no problems setting this up timer using its clever follow-the-instructions-on-the-screen system which seems common to all BG/Hive products. The ONLY thing you really need to work out is whether it's the actual PRODUCT for you!
So, the SCT is a TIMESWITCH only; it can be used to turn your boiler on and off at various set times of each day in 15 minute increments. It will NOT control the boiler temp. It is NOT a Programable 'Stat.
It could just as easily be used to control other items that need timing - outdoor lights, pond features or whatevs. Great item - if it's what you need :-)