Possible reasons for the machine to trip on earth leakage?

I've had the similar EC153b for a decade or so, and its finally showing its age! However I would like to see if there's anything that can be done for it.

I am in UK and so the plug has the third earth pin.

The machine causes my RCD to trip due to earth leakage current when I turn it to heat the water. I read that with coffee machines this can be due to failed insulation on the boiler element, so I was going to take it apart and take a look.

Is there anything else I could profitably check whilst its all open? I notice that the terminals on the top of the boiler aren't fully protected. In fact from past experience opening the machine I think the terminals in mine don't even have those nice connectors like in the pictures.

I also read that blockage could be causing overheating. Would that be in the filter?

Would the fix for the element just be to buy a new one, or can something feasibly be done in a home workshop?

Thanks for reading!