There are a number of reasons a tank could leak:
- The Atomiser head or tank are not properly tightened.
- The coil has been over primed on initial set up.
- The coil has been burnt or come to the end of its lifespan. If this has happened then the cotton inside is unable to hold the E-Liquid, so this may cause the tank to leak a little.
We suggest you check all three to diagnose the problem.