Oil-based cartridges can get clogged when the viscosity of the oil in the cartridge changes, due to changes in temperature. Naturally, when oil is exposed to higher temperatures, it will change to become more fluid; when exposed to colder temperatures, the thicker it becomes. A cartridge exposed to warmer temperatures and cooler temperatures in short periods of time can cause oil to slightly thicken and block the airway to the mouthpiece. If this happens:

Warm the cartridge by holding it upright in your hand for a few minutes. Then try pulling on the cartridge to open the airway. *You may need to pull slightly harder on the mouthpiece to force the airway open. Make sure the battery is not on when opening the airway.* You will hear a small 'pop' noise when the airway blockage is opened.

After warming, try gently blowing into the mouthpiece to open the airway.