Well thanks for the replies, and sorry for causing a bit of a s4!/ storm!
My mcb's are covered by an rccd, all but the lights and fridge socket are not. Unit is Crabtree starbreaker with 100amp main, 63amp, 30 mamp rccd which has 2x32, 1x16 and 1x40 mcb's.
I must admit I wasn't overly keen...