I take it completely apart wash all in hot water dry burn rinse blot wicks and put back together. A lot of the time when you unscrew the top to refill it tends to loosen the head, always watch it. You will see it move. Got some needle nose pliers at hobby nutso and no more probs. Just tighten it up and works great.
just used this method, going to fill now and post results after a few minutes of vaping