Well my suggestion is you learn a bit more before messing around in this
area.

Totally agree with you there, the main reason for asking here

What do you think constitutes a 'good earth' in a domestic supply? You may
well be surprised to find out that is isn't even connected to the earth
(ie
the dirt) outside your house in a PME system.

No, I understand in a PME system, it is connected to the neutral, so a fault
to "earth" would really be a phase to neutral fault, thus making the fault
current higher, making the protection device act as quick as it can...

First step, check is to find out if you have got a PME system- modern
houses
tend to be.

The house was built in the 1920's - What is classed as modern!

PME systems only have two wires back to the supplier - L and N
(note NO EARTH). Nor do they (normally) have an earth rod. The earth in
the
house is no more and all the pipe work etc.. being connected to the
'outer'
of the incoming supply- which is actually the neutral! This bonding is via
a
specified size of wire (6mm as I recall but check) and connects pipe work
etc, incoming neutral, and the earth in the consumer unit.

My generator is PME, as the neutral is bonded to the earth.
However, the instruction manual that came with the transfer switch, also
said I needed an earth rod...

The bloke who came to reconnect me, said the earth cable exiting the bottom
of the incomer would be connected to the armour of the incoming supply
cable - He was also the one who suggested the system was changed to a PME
system..

Sparks...