Beko dw450 trips rcd heating on rinse and gets scorching

Hi and thanks for helping in advance any help is appreciated.

My beko dw450 keeps tripping my rcd on my fuse box. It also geats the water reshot on all program’s including the no heat rinse setting. When I disconnect the heater the dishwasher does not trip the rcd.

I am not sure on whether I need to replace theflow through heater , http://m.buyspares.co.uk/dishwasher/dw4 … ref=479878 , the display pcb ,http://m.buyspares.co.uk/dishwasher/dw450-7674483845/display-module/product.pl?pid=1741744&path=431962,61208&model_ref=479878, or the pcb, http://m.buyspares.co.uk/dishwasher/dw4 … ref=479878.

Or will I need to swap more than one part?

Also the main pcb seems difficult to swap as when I tried to disconnect the heater I could nt so I disconnected it at the heater end.

Thanks again