Hi and thank you for using Just Answer
With regards ***** ***** question, do you hear any noise/buzzing when you turn on the burners?
If not, then the Hobbs you are referring must be the 4 you use most often. With any electrical burner elements, stoves, hot water heater, ovens etc .. the elements have a tendency to wear out. The heating elements after awhile do break down inside after being heated and cooled and it takes longer to get up to temperature. The reason why the repair man never came across it is because normally nobody notices it. They don't call him until it quits completely. It's really nothing to worry about ... common wear and tear. If there is anything else I can help you with, please let me know. I wish you the best.
The only way to take care of the problem is to replace the elements.
Temp of the burners when on is 400 500 Deg C
can the hobbs be replaces individually (6in total) ?
no buzzing noise from burners
Hi, Per your question, yes they can. But if they are not making noise, leave them. 400-500 degree C. is more than enough to get things done. You don't really want to replace them because of the extra 5 minutes it takes. Again this is normal. The time to replace the hob is when they quit working altogether.
These hobs can go along time like this ... so it's really nothing to concern yourself with at this time.
If you have any other questions, please let me know.