Miele Washing machine tripping RCD

Hi,

I have a Miele W526 Washing Machine which trips the RCD on hot washes. My assumption was that the heating element had failed but on further diagnosis I am not sure. Any help greatly appreciated before I buy parts. Here is what I know so far.

1. The heating element is not open circuit (tested in situ) but disconnected.
2. The heating element measures 24 Ohm.
3. A cold wash will not trip the RCD.
4. Any warm wash will trip it if the element is in circuit.
5. Now this is where it gets really weird. If one of the connecting wires and only one of them is connected to either element terminal then the RCD trips. The other connecting wire doesn’t do the same.
6. I can hear what I assume is the relay for the heating element switching and it is at this point (around 5 seconds after water starts to flow via the soap dispenser) that the RCD trips.
7. I have repeated the above back and forth several times to confirm.
8. I have also tested the temp sensor which does vary with temperature so I assume that is OK.

Can it be that the element is really faulty or does the fault likely lie elsewhere?

Regards
Scott