Fan oven tripping RCD after new element

[aidf72]

Hi,
A few weeks ago my Diplomat 3940 oven tripped the RCD, the oven came back on after I reset the RCD but fan element wasn't heating up. The oven still worked on every other function so I assumed the fan element had blown. I bought a replacement element and fitted it (the old one was visibly distorted). When I turned the oven on, it powered on ok so I tested the fan setting - after about a minute the RDC tripped again. Since then, switching the oven on at the wall trips the RCD, even after letting it cool down completely. I refitted the old, blown element and the oven now works again (obviously except for the fan setting). Any ideas what's going on?
Thanks.
Aid

 

[assuhors]

Did the new element come in a sealed polythene bag preferably with a bag of silica gel to absorb any moisture, if not it is probably a new element that has absorbed moisture.

 

[aidf72]

It was in a bag, but there was no silica gel bag.
I tested continuity through the terminals and it was good.
I tested continuity between terminal-earth and terminal-insulation and there was no flow.
I tested resistance from terminal-earth and terminal-insulation and that read as 1 on my multimeter which I believe indicates infinite resistance.
If moisture was the issue, how could I check for it and how would I resolve it?