First, check whether the power supply is plugged in incorrectly. If so, just plug it in again. Let's see if the current or voltage is too low to start the heating coaster.

It is also possible that the quality of the wire for heating the coaster is not good, so the contact is not good. If this is the problem, then you can only fix it. If these problems are not, then there is something wrong with the heating coaster itself.