Steps to prime your coils: Add 4-5 drops of e-liquid directly into the coil head, close the airflow switch, then refill the tank as per instructions. Prior to attaching the tank to the battery/MOD slightly blow air through the mouthpiece about 10 times.
Make sure the airflow switch located at the bottom of the tank is closed before refilling it with e-liquid. If the airflow switch is left open, the tank will leak eliquid while priming the coils.
Open the airflow soon after priming, so you can easily vape.
Questions will help you decide when your coil head need to be replaced:
Sub-ohm tanks and coils have a resistance which is under 1.0ohm. Sub ohm atomisers/coils tend to be bigger, as a result, it can utilise more power, eliquid and cover a greater area of wick. This combination results in massive vapour production.
High-powered device paired is required for sub-ohm vaping (a separate high-drain battery may be required - e.g. the Efest 18650 battery)
"Direct-to-lung" is the suggested vaping style for sub ohm devices (as opposed to "mouth-to-lung" - i.e. how a traditional cigarette would be smoked).
When using sub-ohms tank like the Aspire Kangertech top box nano, its highly recommended to use eliquids which VG is higher than 60% VG and if using nicotine, it must be under 6mg, otherwise you will feel it peppery/harsh on your throat when vaping.
Priming: Whenever you install a new coil you will want to make sure you prime it before using it. Priming a coil will ensure that the wick is fully saturated with e-juice prior to its first use. This would substantially lower down the risk of burning the wick or damaging the coil. Check instruction before use.
Running your MOD at a wattage or voltage higher than the one recommended by the manufacturer might damage the Kangertech SSOCC coils or reduce its life. As a result you might get a dry hit or burn taste when vaping. If that happens you will be required to change the coil head, so you can enjoy a smoother vaping experience.