Thanks everyone for the replies. Went to have a look at the house today. Basically the guys having building work done, but before the building work, he was getting complaints from the tenants that every so often, the rcd kept tripping. He asked the builder to have a look and the builder told him that it is because the circuit was setup as a radial and needed to be changed. When i went and had a look. Turns out the builder was wrong and he’s only good for laying the bricks. The circuit in question was already a ring. Done my tests and found the fault. One of the neutrals was not terminated in the spur socket of the ring. Once fault had been rectified I done rcd tests and everything was fine. No need for altering the circuit at all.
