hi guys, just had a new combi boiler installed, plumber will not wire it. the new boiler is in the same place as the old one, the flex will reach, the fuse rating is the same in the fused outlet for both old and new, the earth bonding is 6mm2 across the pipes/6mm2 back to the cu. am i legally required to get an electrician to do it, or can i do it myself? [ps the boiler is in the kitchen]