The consumer unit (or fuse box as these devices were previously known) should only ever be replaced or modified by competent persons as the work comes under part P of the building regulations.
A replacement consumer unit will require certification for building control and also electrical certification covering all circuits that the new unit is supplying.
Upgrading an old consumer unit to one that incorporates two residule current devices is a job that many people now have to consider ,other options are also possible such as individual rcbo protection for each circuit but this will be more costly.
The 17th edition of the Wiring Regulations (BS7671-2008) requires most circuits of the installation to be rcd protected where cables are burried within walls etc-
We advise customers wishing to have a replacement consumer unit fitted to firstly have the installation wiring tested and inspected.
The reason for this is to ensure that the wiring system is suitable for connection to the very sensetive rcd units ,by testing before fitting we can guarantee that there will be no nuicence tripping due to the wiring within your property.
52 Repton Road
01689 - 836323