Sockets tripping intermittent

[FrodoOne]

Main problem - socket circuit is tripping the boards MCB (not RCD). Have an old board looking around maybe the 80s. ONLY sockets tripping. Everything in home is on one circuit.

ONLY socket (circuit) tripping.

(However, that is one large capacity CU for a "house".)

So, bought a house around a month ago and had intermittent trips on the sockets. I got an electrician round who tested the circuit. The things he found:
- there was a low current, but wasn’t concerned since I lived there by myself without much switched on
- there was a ‘resistance’ on the circuit. So tried to narrow it down and found it was coming from the boiler.

What do you mean by "low current"?
Do you perhaps mean that the supply "Voltage" was low ?

What do you mean by "there was a ‘resistance’ on the circuit." ?
("Series" in the circuit or "Parallel" (leakage), across the Line and Neutral conductors.)

I got to a point where EVERYTHING was unplugged (fridge, oven, Washer, office upstairs, chargers, TV, router etc) nothing was in the circuit. Tripped again.

If "EVERYTHING was unplugged" the fault must be in the wiring of that which is (presumably) a 32 A "Ring" circuit, feeding all of the "Socket Outlets" in the premises.

I suggest that you examine all of the Socket Outlets, their connections and the "boxes" in which they are located to see if there are any discernible (short-circuit) faults.
(With a 32 A MCB, any short-circuit should leave significant "traces".)

Since it appears that there is a (short circuit) fault on that "Ring" (and you have many spare MCBs), you may consider "splitting the "Ring" into two "Radials" on each of two MCBs, of appropriate capacity.
From this, you will be able to determine on which "half" of the "Ring" the fault exists - when/if it occurs again.

Then, you could
restore the "Ring" and then
"split" it into two "Radials" at a different point in the previous "Ring".

Yes, this will be "tiresome".
However, you do need to locate the "section" of the existing "Ring" where the intermittent short-circuit fault exists.

Having all of those apparently spare unused MCBs with only one "Ring" for all of the Socket Outlets is "unusual" - to say the least !
You should consider using "Radials".