Is it analog (dial temperature setting) or digital? - If it is analog, your thermometer and the dial may not be calibrated correctly. - There is a small set screw on the bottom of the dial. It got loose on mine and caused issues.
I used a thermometer to measure the temp of the chocolate when the lights were coming off and on. - Then loosened the screw and set the dial to that temp. - Life was easier and better after that.
Is the machine heating too much? Is the chocolate getting too thick?
Could you share pictures and be much more descriptive?
Also, Hilliards has pretty good customer service. They may be able to help.
We are going to need a little more detail than this to help you out. What kind of chocolate? What temperatures ... also in the room you're working in. How you're cooling, and more.
Have you been in touch with their technical support?