I have a Fisher & Paykel CE901M electric cooktop. The two small burners (1200W) will start heating normally and then occasionally get too hot and stay hot until I turn the burner off. This happens when trying to simmer a sauce or cook something at low heat. I replaced the "energy regulator" that the knob attaches to on one of the burners to determine if that was the cause. It didn't solve the problem. Any input would be appreciated.