I have a Britannia SI-10T6-SLX-S (I know it’s an older model) when I use the left hand oven to make bread and have the temp at 250 it trips the rcd, this only happens occasionally but is becoming more frequent what with lockdown baking. I have had an electrician replace the MCB and RCD and check the cables to the cooler switch and it’s all fine. Now it’s starting to do it at lower temperatures too tripping at 200 yesterday. What can the issue be?