Maria, box it in (all of it).
Alternatively cut down a cupboard and stick a door on the front,
making the cupboard lift-off (you can buy brackets which lift off).
The instructions will say what ventilation it requires, as in a bottom
vent & top vent of certain area etc.

Remember to fix the hole in the ceiling, just in case you miss it (!).

I would have moved the SFCU on the RHS further away from the pipework,
but that is just me. Others cable tie the supply cable to the lead gas
pipe, making it festoon on its cramps, but the cable ties are at the
correct spacing for the cable diameter...