Turn up heat on the vaporizer. If the heat is all the way up, the heater could have fallen in the unit. Make sure the heater is straight in the glass, and sitting up high in the heater cover. The heater should be about 1/8 inch from the top of the heater cover. Check the Light on the unit: Does the light come on? If the light does not turn on the issue is the dimmer switch. If the light does come on, does the light brighten and dim when the knob is turned? If the light does function correctly and the element is not heating correctly, then the issue is the element. If the light does not function correctly by turning on or brightening and dimming, then the issue is the dimmer switch.