Unfortunately for us (and luckily for you!) we've all been there - you've filled your tank, and it's leaking. There are a variety of reasons a tank can leak e-liquid, and we'll cover some of the basics of fixing that leaky tank for you right here!

Please remember that this is a general guide; every tank is different, and some of the fixes here may not be applicable to your specific tank. We've tried to be thorough, but some tanks will be put together differently or need to be filled differently. Your tank's user manual may have additional steps for you to try!

Before we get started, here are a few terms we'll use throughout this article:

Base - the bottom piece of your tank that connects to your device

Airflow Holes - the holes (usually in the base of your tank) that allow air to flow into your tank and up through the coil, creating vapor

Coil - the atomizer or coil head you screw into your tank

Top Cap - the top part of your tank which usually attaches directly to the coil; some tanks have a two-piece top cap with a fill port in one piece, and a mouthpiece/cover in a second part

Mouthpiece - also called a drip-tip, this is where you put your mouth when vaping

Glass - the outer glass (or plastic in some cases) of your tank

Chimney - the center of your tank, not including the coil itself; this includes the hole through your mouthpiece as well as the hole that connects to your coil inside the top cap - when looking down at your fully assembled tank, you're looking through the chimney, into the coil. 

Fill Port - this is usually in the top cap of your tank, if your tank is filled from the top (some tanks must be disassembled and filled upside-down, though) and is usually 'around' the chimney of your tank

Gasket or O-Ring - these are the plastic rings and seals that prevent leakage in your tank and are located on most or all of the places where glass, metal, or plastic connect - these seal your tank from leakage

Before you start troubleshooting... 

We always recommend examining your tank closely to see where the leaking is coming from and then emptying, cleaning and disassembling your tank before you work through figuring out why your tank is leaking. This way you can look at all the separate parts individually and see quickly if there's a problem with the tank or coil, missing o-rings, and start with a fresh coil and a fresh assembly (steps below). Be sure to keep track of all the individual pieces, including the original coil if it's a new tank, as if you can't fix the leaking and need to make a return all parts including original coils, spare parts, and packaging, must be included in your return.

Where is the leak coming from?


Most of the time, when your tank is leaking, the e-liquid is going to come out of the airflow holes - this means that the leak source is somewhere inside the tank/around the coil. 

However, if you're seeing e-liquid leaking from the spots where the glass connects to the bottom (base) or anywhere other than through the airflow holes, this usually means that there's an issue with the gasket or o-ring that should be seated in that particular spot. These pieces of soft plastic help to seal your tank and prevent leaking, but they can get old and stiff, or be damaged by over-tightening your tank, and replacing them from the spare o-rings or gaskets that come with most tanks or getting a replacement o-ring or gasket from the tank manufacturer will usually fix these issues right away. Putting an incorrectly sized o-ring or gasket on your tank can cause more leaking, though, so be sure to get the correct size!

Checking O-Rings and Gaskets

Leaking through the airflow holes can also be a problem with the gaskets and o-rings inside your tank - the ones on your coil, and on your bottom and top cap where the coil connects to each piece. Checking to make sure all the o-rings and gaskets are in place, seated correctly, and aren't damaged may help you locate the leaking issue, and simply replacing or 'putting right' the missing, improperly placed or damaged o-rings should fix the leaking issue!

Coil Issues

Once you've confirmed that all the o-rings and gaskets on your tank and coils are there, undamaged, and in the correct place for your tank, you'll want to take a look at your coil. Aside from improperly seated o-rings on your coil (usually there is an o-ring at the top, and at the bottom, of every coil, but it depends on your tank - the Falcon coils, for example, only come with an o-ring at the bottom of the coil itself) there are a few reasons e-liquid may come through the coil too quickly and cause leaking (or spitback/flooding!).

  • Use the correct e-liquid formulation for your coil. Some coils are intended to be used only with nicotine salt liquids, and some coils are not made to be used with nicotine salt liquids at all. Most of the coils we sell should work well with liquids that are about 70% VG. Extremely low VG liquids (very thin liquids) aren't intended to be used with sub-ohm tanks and will work best in high-resistance tanks like the ET-S Clearomizer or all-in-one devices. If you have questions about what PG/VG ratio or formulation you should be using with your coil, please feel free to check in with our customer service team - we're here to help!

  • Vape at the correct wattage/power level for your coil. Using wattage that is too low or too high for a specific coil (most coils list the recommended wattage range, and you can find this information on almost all the product pages for the coils we stock) can cause a variety of issues, from leaking tanks, to scorching the wicking material in your coil, which will make your vape taste awful and will also damage the integrity of the coil itself, which causes leaking too! If you've already been using a coil at the incorrect wattage, you may need to try with a fresh coil at the correct wattage for that coil. If you started out at too high a wattage on a fresh coil, your wicking material may already be damaged. 

  • Prime your new coils. We recommend 'ramping up' your wattage when you're breaking in a fresh coil. Once your brand-new coil is saturated with liquid (fill your tank and let it sit for about five minutes. You can also draw on it with the airflow closed, not firing the tank, to speed up this process - but be warned, this can cause your coil to flood and then leak if you draw too hard or too many times! You'll see the top of the coil is damp when you look down through the chimney at it and know it's saturated and ready to start vaping; if you're doing it 'fast' we recommend checking after every draw.) start at about 10-15 watts lower than you normally vape at and increase your wattage in increments as you break the coil in. Our customer service department member who vapes around 70 watts, for example, will start a coil out around 55 watts and increase it 5 watts at a time with a few draws (firing the device this time, of course) at each level. Be sure to give your coil about 30 seconds to wick between draws as you do this. If you vape at a very low power level or with high-resistance coils, just a few watts lower (start at 12 to get to 16 for example) will do just fine. Please keep in mind that as you break in/prime your coils, your e-liquid won't taste as good as it will once your coil is ready to vape normally.

  • Change your coils regularly. If your tank is leaking and the coil you have installed during the leakage issue is darker in color than the liquid you use, you may need to replace the coil. While there is no 'set' amount of time a coil will last (there are many factors involved in coil longevity) you'll usually know it's time for a change when your e-liquid no longer tastes as good as it should, when the coil itself is taking on dark color, and when it's no longer wicking properly - leaking and dry hits are big indicators that it's time for a coil change!

Re-Assemble Your Tank

By now, you've confirmed that all the parts and pieces of your tank are intact and in the correct place, you've checked your coil (and gotten a new one if necessary) and made sure that you're using the correct settings and e-liquid for your tank. This means it's time to reassemble the tank and give it another go!

We recommend assembling your tank step-by-step, of course, but where you start depends on which type of tank you have. If your tank is a bottom-fill tank, always assemble from the top down (upside down). If your tank fills from the top cap, always start at the base and work your way up to assemble. Basically, you want to put your e-liquid in right before attaching the final piece of your tank!

First, whether you're starting from the top or the bottom, you'll want to attach your coil to the base (or top cap for bottom fill tanks). You'll want to attach this piece and all parts to finger-tight. That means that when you attach it, you'll want to screw it in as far as you can without putting excess force on the pieces. If you over-tighten, you can damage the seals on your tank - which causes leakage! If you under-tighten you'll leave space for e-liquid to leak through, so no part should be 'loose' when you attach it, but don't force any part of your tank down or in.

Then, you'll want to attach/slide on your glass or plastic to your tank. Be sure that the glass is on straight, and that it's seated snugly on the base (or top cap for bottom-fill tanks). If it's crooked or loose, you won't be able to completely assemble your tank.

The next step depends on your specific tank. Most of the tanks we carry are top-fill and have a fill port in the top cap. If this is the case, go ahead and attach your top cap to the tank. Again, usually this item is screwed onto the top of the coil - you'll want to screw it on gently, making sure everything is aligned correctly, to a snug fit, but don't force it further than finger-tight. If you have a bottom-fill tank or a tank that requires the top cap to be off completely to fill, go ahead and fill your tank as detailed below before finishing assembly.

Fill Your Tank

Once your tank is completely assembled but still 'open for filling' you can go ahead and fill your tank. Every tank is a little different, but there are a few general rules to remember:

  • Never put e-liquid into the chimney or directly into the coil. You will always fill 'around' the coil, or through the fill port for your tank. If you get e-liquid down the center tube of your tank and directly into the coil, it will all leak out!
  • Close your airflow while filling. This helps in some tanks, and is required in some tanks, and in others, it doesn't matter too much. Your user manual may have tips on filling that include this note, but it's best to try with the airflow closed at first, if that's an option on your specific tank. Just be sure to open up the airflow once you're ready to start vaping your e-liquid to your preferred amount!
  • Never overfill your tank. Some tanks have a 'max fill level' shown on the tank - don't fill past that line. Many do not have this, but you'll want to fill your tank to 'almost full' in these cases with a small amount of air left in the top. Leaving a little air at the top of the tank actually helps to create the vacuum that keeps your e-liquid from leaking out.
  • Don't underfill your tank. This is a great rule in general. If your e-liquid level drops below the wicking ports in your coil, it's time to refill - this helps keep your coil in tip-top shape and prevents dry hits.
  • Tilt your tank while filling. Not all tanks require this, but it can be helpful to tilt your tank slightly as you begin filling (like pouring a carbonated beverage into a cup) and then straighten it as you get toward the top. This helps to keep your liquid from going into the chimney/coil of your tank especially with some bottom-fill tanks.
  • Let your tank sit! As we discussed earlier, you'll want to let your tank sit with the top cap or base on, and let the coil soak up your e-liquid for a few minutes (5-10) before starting vaping. You will know when it's ready by looking at the coil through the chimney - the top will be saturated with e-liquid once your e-liquid soaks up from the coil ports into the full wicking material. If you prep your coils by putting a few drops directly onto the coil, you'll still want to let it sit, but we don't usually recommend doing that - it makes it hard to tell when your coil is saturated properly!

Once you've filled the tank with e-liquid, put the top cap on (or base) promptly (while you let it sit and soak up your juice). This also helps create the vacuum to ensure the right amount of e-liquid is wicking into your coil. Be sure that everything is secured (but not overtightened) and that there are no gaps. You can open it up to check the coil after 5-10 minutes (before you start vaping), but unless you're actively checking the coil or refilling your tank, you should always have your tank fully assembled, with all parts on securely. Leaving parts off or open can cause leakage. After your coil is saturated your should be ready to prime your coil and vape away!

Vaping Tips

Sometimes how you vape makes all the difference. Drawing on your vape in a slow, controlled manner will help with your coil longevity and prevent leakage. If you're drawing hard on your vape, you're going to 'pull' too much eliquid through the coil - which causes leaking and can cause juice to come up into your mouth. Unlike with traditional cigarettes, pulling hard on your vape won't produce more vapor. Your vapor production / amount of vapor you get is controlled by your airflow, so long, smooth (but not hard) draws will give you big clouds and more vape, and so will opening your airflow control ports to the maximum amount. 

If you want big clouds, just take a longer draw. This can cause your vape to become 'harsh' though - so we usually recommend starting out (especially when priming) with gentle, short pulls of vapor into your mouth. Everyone is different, so experimenting with short and long draws, and inhaling vapor into your mouth first, then inhaling; or inhaling (gently) directly into your lungs, is the best way to figure out what is most satisfying for you. What you do and don't like will be clear with some experimentation!

You also want to keep in mind condensation. All tanks (except the Uwell Crown IV, which has a special design to help with this) will build up liquid in the base over time. This is because not all of the vapor you produce gets inhaled, and it will slowly build up over time inside your tank. Cleaning your tank every time you change the coil helps; so does letting your tank 'drain' on its side every few days if you don't need to change the coil. You can reduce condensation by doing two things:

  • as soon as you start firing your tank, start pulling the vapor in
  • continue inhaling until just after you release the fire button to make sure that all the vapor you've created is going into your mouth

Of course, keep in mind how you prefer to vape when doing this!