Induction hob error E6

I have a Falcon oven with induction hob. 2 of the 5 rings on the hob are showing an error message E6. A repairer has been to inspect it, and has advised getting a new circuit board - Rangemaster Pcb (5045176234441) - costing £380. This spare part has been on order for three months, and there is still no sign of it. I see from your website that the error may be caused by a faulty temperature sensor or other reasons - something not mentioned to me. Any advice as to what I should do? Is the replacement of the circuit board an appropriate remedy for E6?