Learn how your appliance is supposed to operate so you can determine if it is malfunctioning.
There have been several manufacturers that have produced different styles of element switches over the years. The most popular element control switch in use to this point has the "Infinite Heat Switch" manufactured my Robertshaw. Corox and King Seeley marketed their own types of element switch referred to as 'wattage sensitive' switches. Those operate on a slightly different principle but for our purpose can be considered similar enough and the tests described likely appropriate to those as well.
If your range's surface element is not heating at all and a check of the element and wiring didn't turn up any problems, there may be a problem in the control switch. For the element to totally not heat, no power can be getting to it. If a good element was getting power it HAS TO heat. There are no two ways about it!
The switch for the element will need to be accessed to have tests performed on it. Disconnect power from the appliance by either turning the house breakers off or unplugging the range from the wall. The rear panel of the range may need to be removed to access the switch wiring and terminals. On some newer range models or models with upfront controls, access to the switch terminals and wiring may be able to be done from the front.
When turned "ON", the switch contact connecting terminals L1 and H1 closes and the contact between L2 and H2 closes. When the switch cycles power to the element to control its heat, the switch opens the contact between L2 and H2 stopping power flow to the element. The contacts between terminals L1 and H1 remain closed the whole time the switch is in an "ON" position.
If the element stays on "HI" regardless of the knob setting, the L2 to H2 contact is likely shorted closed. If the element stays on "HI" even when in the "OFF" position, both the L1 to H1 contact and L2 to H2 contact are shorted.
The first test that can be done is checking the switch contacts for continuity. This must be done with power disconnected from the whole appliance and wiring removed from the element switch terminals.
With the wiring disconnected from the switch and the switch in the "HI" position, there should read continuity between terminals L1 and H1. There should also be continuity between terminals L2 and H2. If either of those tests show no continuity (ie. infinite resistance), the switch is likely defective and needs to be replaced.
The wiring diagram is for a Robertshaw infinite heat surface element control switch. If your switch terminal numbering differs, consult the range's wiring diagram or the images above to try to ascertain the correct terminals to test between.
If the above tests check out and there is no problem in the wiring from the switch to the element and the elements tests as good and you are still not getting any heat from the element, someone will have to verify that 240 volts is getting to the L1 and L2 therminsals of the switch. There may be a problem with the range's wiring leading up to the switch. If 240 volts is present at terminals L1 and L2, someone can confirm power out of the switch by checking for 240 volts between switch terminals H1 and H2 with the switch set on "HI".
Testing on a 'live' appliance can be dangerous! Anyone unfamiliar with proper safety precautions should not attempt it.
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.