Your SERIES-E doesn't require much regular maintenance, other than changing the coil every 5-10 refills and making sure that all threadings are not over-tightened. You can find out how to change the coil.
Also, make sure that no threadings are over-tightened as this can cause parts to seize up and become difficult to undo. Just finger-tight is enough!
It is recommended that you keep an eye on all of the connections and threadings to ensure that nothing becomes cross-threaded and that they are kept clean and free from debris. Also, over time, e-liquid will build up on these connections so you may want to clean the tank every few weeks. To do this, open the tank as if you're going to fill it, and remove the coil. Rinse both parts of the tank in warm water, or leave to soak in a mug of warm water for 15-20 minutes and then rinse well. Take a pin and poke through the airflow holes to ensure they're free from any blockage. Leave to dry completely, install a new coil, fill, and you're all set!
You will also need to check the condensation trap, which is found by removing the mouthpiece. Vapour which has condensed back into liquid may build up here, but this can be simply wiped away with some tissue.
To clean the connections on your vape battery, run a small screwdriver or pin around the connections on the top of the battery as this will clear away any built up dust or debris.
Please be aware that the SERIES-E kit is no longer available, and this is due to the TPD regulations. However, we do have a great selection of other starter kits available, including new vape pens so please check the JAC Vapour website if you're looking for a new kit.