My fridge freezer keeps tripping the RCD in our consumer unit. It’s not the supply as I’ve tested it in another socket. I’ve also cleaned all the electrical connections I can get to at the back of the fridge. When it runs all seems fine. The problem has been getting steadily worse. Now it either runs for about 5 mins or trips out immediately the RCD is reset. Our fridge is 14 years old. Any thoughts?