I am not familiar with the protank 3, however there are a couple things that might be causing this issue. What
juice are you using? Vg heavy juices (juices that have a lot of vg) tend not to wick as well in tank systems as 50/50 blends. So if you are using a vg heavy
juice, try using a 50/50 juice. Also Is your mod variable voltage and/or variable wattage? if so, try turning down the voltage or wattage. This will allow the coil to heat up more slowly, and get hot less quickly. If you have your mod cranked all the way up, that could be causing these dry hits. I know the protank does not have adjustable airflow, so maybe even experiment with different drip tips (if you have some). If you are using a really wide bore drip tip, this can make it more difficult for the juice to wick properly. Also, try plugging the airflow hole with your finger and drawing through the drip tip. This will draw juice directly into the chamber. Also, sometimes these clearomizer replacement coil heads can just be duds. In my experience you will occasionally get one that just does not work right and you have to move on. If you switch out the replacement heads and you still have this problem, maybe even try purchasing higher resistance replacement heads, as they will produce a cooler vape, and heat up less quickly. Hope that helps.