on top of all the great info in those threads there is one other thing to check...don't get me wrong, I've had over 30 different Kanger tanks from the CEX all the way up to the new subtank mini and this only happened on one, but it's still possible....on top of looking at the o-rings, seals, and making sure you don't over fill the tank and you can turn it upside down and blow threw the airholes like a Kayfun to equalize and clear things out there is one more thing to check for
one one of my protank 2's when they first came out back in 2013 I had one that wouldn't feed right and dry hit after dry hit no matter what I did, I replaced the o-rings, went threw multiple coils, and still nothing worked...then one day when I held it just right in the light I saw the center post was slightly crooked....it was ever so slight but it was enough to keep the center post from sealing against the coil properly and screwing everything up. They're more than likely just press fit in just like the protanks so you should be able to take everything completely apart and take a pair of pliers with some paper towel or a bit of cloth inbetween the pliers and the centerpost and move it with some careful effort....I am not by any means saying this is what is causing your problems....but if all other possiblities are exhausted than that might be one final thing to check...best of luck to you
