There could be 2 reasons for this.1 is that the heater cracked and broke.2Nd is that the heater is not fully screwed in. If you feel it is tight let’s look at why maybe the heater broke. The heater can burn out for a few reasons. First, if you use a mod and take the heater past 10 watts or 3.7 volts it could get too hot and crack the ceramic. You can run the heater above 10 watts or 3.7 volts, but you do this at your own risk. You need to have enough concentrates to have them over the heater. If the oils are too low and under the heater too cool, and the heater will get too hot, sadly cracking the ceramic and burning out the heater. Do not ever use dry herbs or hash in your Wax Maxer vape pen.