Hello, I'm not sure if you've taken acs exams yet, but if it's your initial then the centre may give a few nudges in the right direction. If it's a re-assessment then you ought to know some stuff? My advice is look for anything that stands out as different, incorrect fittings, gaps where there shouldn't be any, sooting, etc. Listen to the question/scenario being asked and if you're not sure - ASK, refer to mi's or bs5440 parts 1-3. Good luck.