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MTL, RDL or DL: Which Draw Style Suits You?
MTL, RDL or DL: ohm, watts, airflow, e-liquid and nicotine strength compared by draw style, and which pod system or tank suits your draw.
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Coils and Vaporiser Heads: Changing and Priming Them Properly
A prebuilt coil is replaced when the flavour keeps tasting burnt or fades noticeably at the same settings. Priming means saturating the cotton with e-liquid before the first puff. Which head fits and how many watts it can take depends on the specific device.
In this article12 chapters
- Coil, head or whole tank?
- What is a coil?
- When do you need a new coil?
- How do you change the vaporiser head?
- How do you prime a new coil?
- What does the ohm value tell you?
- Which coil fits your device?
- Heads and tanks in pictures
- Which e-liquid wicks well?
- What helps with burnt taste, gurgling and leaking?
- What is different with a mesh coil?
- Frequently asked questions
Coil, head or whole tank?
| Term | What you replace |
|---|---|
| Coil / vaporiser head / head | Ready-made insert with heating wire or mesh and cotton |
| Atomiser / clearomiser | The whole tank system with mouthpiece, tank and seat for the head |
| Pod with fixed coil | The complete cartridge once the coil is used up |
| Pod with replaceable coil | Just the individual head; the undamaged pod stays |
What is a coil?
In everyday use, coil usually means the complete vaporiser head. It contains cotton and a heating wire or mesh. The cotton absorbs e-liquid, which evaporates when heated. The actual winding is also called a coil – which is why the word appears with two meanings.
With a prebuilt coil, you replace this insert as a whole. A rebuildable atomiser is maintained differently: there, the winding and cotton can be renewed individually. The steps here apply to prebuilt coils and refillable pods.
When do you need a new coil?
If the head keeps tasting burnt, you replace it. Burnt cotton does not become usable again by refilling or rinsing. A clearly weaker flavour and less vapour at the same power can also point to wear.
A fixed replacement interval does not suit every kind of use. E-liquid, power and the pauses between puffs affect how long a head lasts. Sweet e-liquids can build up residue faster. Change the head according to its condition rather than waiting for a calendar date.
If you notice gurgling, leaking or spitting, first check condensation, coil seating, seals and fill level. The troubleshooting overview separates these causes.
How do you change the vaporiser head?
Some heads are screwed in, others are pushed in. With a pod with a built-in coil, you replace the whole pod. The photos show the tank and replacement heads as components; the way to open and change yours depends on your model.
Switch the device off
Switch the device off and detach the removable tank from the box mod, or take the pod out. Have a cloth ready. With systems that must be emptied for a coil change, remove the e-liquid beforehand.
Replace the head
Open the tank or pod as shown in its instructions. Unscrew or pull out the old head. Insert the matching replacement straight and fully. Seals must not slip; tighten a thread by hand only.
Fill the tank
Fill through the opening provided for it, not through the air channel. Keep to the tank's fill limit and close the cap. Dry the contacts if e-liquid has got onto them.
Let the cotton saturate
After filling, wait for the time given in the instructions. New heads need several minutes. Only fully soaked cotton can handle the first puff. A prebuilt coil is never dry-burned.
Set the power
Start at the lower end of the wattage range stated on the head or its packaging. Increase within that range. For devices without wattage selection, use the coil or pod intended for them.
How do you prime a new coil?
Priming means wetting and soaking the cotton before the first puff. With individually replaceable heads, you can put a few drops onto the visible cotton in the e-liquid openings before inserting them. Then fill the tank and let the head stand. With closed pods with a fixed coil, filling followed by a waiting time is enough.
The time needed depends on the model: some instructions state five minutes, others ten or more. Follow the instructions for your system. The first puffs are no substitute for soaking. Dry cotton can burn as early as the first firing.
Afterwards, keep making sure there is enough e-liquid above the minimum mark. With many puffs in quick succession, the cotton needs time to absorb e-liquid again. Dry-burning is not part of looking after a prebuilt coil.
What does the ohm value tell you?
| Draw style | Airflow | What matters when choosing a coil |
|---|---|---|
| MTL / mouth-to-lung vaping | Rather tight | Head approved for MTL and a suitable wattage range |
| RDL / restricted direct-to-lung | Medium to open | Suitable RDL head; the air supply limits the draw |
| DL / direct-to-lung | Rather wide open | Head designed for DL and sufficient power |
Ohm describes electrical resistance. Below one ohm is called sub-ohm. That does not determine the draw style: there are also MTL coils with less than one ohm. Airflow, design and power range count together. A fixed ohm limit between MTL, RDL and DL therefore does not work.
First choose a head intended for your device, then the suitable power range. A wattage figure from a different coil series cannot be transferred. MTL, RDL or DL explains the draw techniques in more detail.
Which coil fits your device?
Compare the exact device or tank name with the head's compatibility list. The same brand name, the same resistance or a similar shape are not enough. Even within one coil family, a tank may only accept certain versions.
An example: Aspire does not recommend the Nautilus 2S head with 0.4 ohm for the original Nautilus and Nautilus Mini. GTX and GTi from Vaporesso, in turn, are different platforms. Check the specific tank and the specific version; do not force a fit by pressing or screwing in incorrectly.
The vaporiser coils are the shopping starting point for replacement heads. The following pictures show designs and tanks, not mutual interchangeability.
Nautilus 2S
Slim head with thread. Check the specific Nautilus tank and the coil version.
Nautilus BVC
A similar outer shape does not mean all resistances are freely interchangeable.
BP Mesh
Coils from a different platform. The BP name is no substitute for matching the device.
AF tank in blue
A complete tank rather than an individual head. It has a seat for matching replacement coils.
Nautilus 3 tank
A replaceable head sits in the complete tank. Choose the coil version intended for it.
Which e-liquid wicks well?
A high VG share makes e-liquid thicker. With small e-liquid openings, the wicking can become too slow. Conversely, very thin e-liquid in a system not matched to it can encourage flooding. The ohm value alone does not determine a fixed mixing ratio. Check the specification for your head or pod.
How to read the proportions and calculate them when mixing is explained in PG and VG explained. A different e-liquid repairs neither burnt cotton nor a faulty seal.
What helps with burnt taste, gurgling and leaking?
| Symptom | Check first | When to replace? |
|---|---|---|
| Constantly tastes burnt | E-liquid level, soaking time and wattage range | Replace the burnt head; prime the new one properly |
| Flavour or vapour fades | E-liquid, battery charge and unchanged settings | If the head is used up after these checks |
| Gurgling or hot droplets | Condensation and excess e-liquid in the air channel | If the head is damaged or worn |
| E-liquid leaks | Coil seating, O-rings, cap and fill limit | Replace the faulty component; a coil change does not fix a cracked seal |
| Coil is not recognised | Switch the device off; dry the contacts, check the right head and seating | If the head is damaged; check a persistent device fault separately |
For burnt taste with pods, there is also the article Pod tastes burnt. If a device fault persists despite a correctly inserted head, do not keep firing and check the device.
What is different with a mesh coil?
Mesh is a net-like heating structure instead of a classic wire winding. Either can sit in a prebuilt head. The term mesh says neither which tank the head fits nor which wattage you should set. A mesh coil is saturated with e-liquid before the first puff in just the same way and replaced when worn.
Frequently asked questions
Can I wash a prebuilt coil?
Rinsing does not make a used-up head new again. Replace it. You clean the tank separately; contacts and all parts must be dry before reassembly.
Why does a new coil taste burnt straight away?
Often the cotton had stayed dry or the power had been set too high. Check soaking time, fill level and wattage range. If the cotton is burnt, you need another head; refilling does not remove this taste.
Can I use a 0.8 ohm coil for MTL?
Yes, if the specific coil and the device are designed for MTL. A resistance below one ohm does not automatically mean DL. The approval for the device and power range decides.
Do I need a new coil when changing flavour?
A coil that is still usable does not have to come out just because of a new flavour. The previous taste may linger at first. If you want to avoid this mixing, insert a fresh head.
Can I keep going with a pod without a replaceable coil?
Once the built-in coil is used up, you replace the complete cartridge. Breaking the head out of it is not an intended way of changing it.
Why does the tank leak after a coil change?
Check whether the right head is fully seated, all O-rings are intact and the tank is closed correctly. Keep to the fill limit. The fault may lie with a seal or the seating.
About the author
Philip
Vape veteran
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