Our de dietrich induction hob has started beeping and won’t stop. The 2 rings on the right and the large ring in the centre are working fine but the 2 rings on the left won’t turn on! The beeping is continously even when I’m using the working rings. I’ve turned it off at the mains and left it over night and turned it back on but it’s still beeping. Any ideas what the problem might be and how to fix it…or is it going to be expensive to fix? Any help greatly appreciated 😉