Learn how your appliance is supposed to operate so you can determine if it is malfunctioning.
Smooth top ranges utilize radiant or halogen elements which are mounted beneath the glass cooktop. A standard radiant element uses a resistance wire to generate heat similar to a conventional coil element but for the most part that wire is exposed on the surface of the element rather than sheathed. A halogen element has a similar open resistance wire plus an additional quartz bulb.
Since the glass cooktop surface can not withstand as much heat as a metal cooktop could, there is also a safety precaution to help prevent overheating and damage to the glass. That is accomplished using a thermal limiter switch.
The limiter used on radiant elements serves two purposes; it protects against overheating by shutting down power to the element should it become too hot and also contains a switch which when hot allows a 'hot surface' indicator light to display on the range for personal safety. The hot surface indicator light contact of the limiter switch should close (ie. make contact) once the protector senses 150°F.
When the limiter on these elements fails it will usually totally prevent the element from heating. However, the limiter can also fail resulting in just the hot surface indicator light remaining ON even when cool or less commonly, trip prematurely preventing the element from reaching full heat.
Sometimes the limiter itself can be replaced but more often than not, when it fails the whole element and limiter assembly needs to be replaced to correct the condition.
The replacement limiter may be from a different manufacturer and may have different terminal positions. You should usually go by the terminal markings (1a, 2a, etc.) rather than their position to insure proper connections.
To access radiant elements and their wiring the range top usually has to be raised. On most models there will be screws or spring clips along the underside of the front edge of the cooktop. Open the door and examine that area to see if the elements on your particular model can be accessed that way.
All of the information in these Appliance Clinic procedures is provided FREE OF CHARGE. No liability is assumed by the author for the accuracy of the contents or damages caused by the use of these procedures.