It`s 2 years at college for your NVQ level 2 Plumbing course then I think another 2 or 3 years to do your CORGI certificate, but you`ll be lucky to get in coz I`ve heard there`s a massive waiting list now.
I`m not sure about sparky courses but I`d have thought it would be the same story.
Get in touch with Sheffield or Chesterfield College to ask about vacancies.