Domestic Appliance Forum

Hi, I have had a brand new AEG induction hob fitted which is constantly switching itself off with Error code C1 followed by E9. The engineer has come out and replaced the mother board as apparently this is the E9 error code but unfortunately it is still occurring. No one seems to know what C1 means. So the engineer has been unable to fix the hob. They have replaced the hob entirely. But the new hob is also erroring with C1 then E9. I’m at my wits end now!
Can anyone find out what C1 means.