Different Wire Sizes of Load Neutral and Ground

2.5sq mm for phase and neutral and SWG 8 for ground or earth.

your water heater is standing alone 250mm near a distribution board??...it is dangerous.....do u have the cable size in the range of .5,1,1.5,2,2.5,3,3.5,4,4.5,6,6.5,7....................?

a wall socket installed of rating 16amp near db . the socket is used for heater wires from mains/isolater to socket(1sqmm ground wire, 2.5 sqmm neutral wire, 3sqmm load) different wire sizes used which are readily available at home is this kind of wiring dangerous? also i don't have bus bar these wires are tied together with other lines at isolator/mains

The Installation is not as per the IEC/BS regulations. wire size is wrong.!!!! about dangerous...say you can ride a motorcycle with helmet or without helmet. Which is dangerous???

It isn't wired to British Standard 7671, as there's no such thing as a 16A domestic socket in the UK.

So, what does the relevant national electrical safety code have to say about it?

A bucket of water is dangerous - one can drown in it!