We have a Siemens fridge freezer KA62DS50GB/01 (FD9104). It’s about 4 years old and has recently started intermittently tripping the power in our house. When I do the automatic self test programme it trips when it gets to L13 in the test. It trips before I get an error code. Can anyone advise what part of the self test is L13. I am hoping this may help identify what part is mal-functioning. Thank you.