Yes without doubt this is the Thermostats causing your problem! Obviously make sure the element is also checked before considering the thermostats.
Make sure that you give the dryer a good clean through removing any lint or dust build up. Some times these thermostats can fail if the door is constantly opened while the unit is still running.
Obviously you are an electrician so no need for me to tell you how to check the thermostats.
Carlito Corway
November 2006