Ideal Icos m3080 - Fuse Location?

My Ideal Icos m3080 boiler has packed up [again!].

I think it is the PCB fuse (a 3.5AT L250V). In the handbook this is item 37. However, the book doesn't say where this should be located. The PCB itself doesn't seem to have a 'slot' for this and has stickers on it saying no serviceable parts inside.

Can anyone please help?

Many Thanks!