Boiler & Manifolds
The boiler is a Saunier Duval Therma F24e Plus.
Full instructions may be found here.
Top left: Utility Cupboard; Top right: Valley Cupboard; Bottom Left: Attic; Bottom Right: Kitchen Behind Hob
There is a black box next to the boiler which controls the boiler and heating. There is no reason to touch this. The three lights on the top should be on.