Initially there was a casual phone call followed by a telephone interview which included some verbal technical questions, nothing too hard, Then a personality questionnaire was emailed for me to complete, this was a 5 minute multiple choice thing, very straight forward.
I was then offered an interview in person with my potential line manager at a casual place convenient to me. In this interview I had to complete a written technical exam followed by some verbal synario questions. The interview felt more like a catch up with an old friend, I was then offered a position by email. This was the followed by a 2 day induction process at the Head office. Overall it was a very relaxed and easy going process, everybody involved was super nice, the tests weren't especially hard, I would say that they were well thought out questions which were clearly designed to help judge compatency at diagnosing boiler faults.