Why isn't temperature control working on my e-cigarette device?

E-cigarette temperature control, a feature found on the more advanced vaping devices, is something that many seem to struggle with. It's not hard to understand why, when all they have to guide them is a poorly written manual, that often presumes a certain amount of vaping knowledge.

I've seen e-cigarette manuals that say nothing more than 'A temperature control compatible coil must be used.' Once you understand how it works and why you would to use it, things do start to get a little easier to understand and getting it 'working' correctly shouldn't be too much trouble.
Lets get the wire issue out of the way quickly (I'll try and keep this simple). Most vaping coils are made from either Kanthal (KA1) or Nichrome (Ni80). The reason being that those metals are stable when heated. This means the resistance of the wire hardly changes when it gets hot. Resistance is part of the 'Ohm's Law' equation, as is wattage. Put simply, if the resistance of the coil is changing dramatically when heated, then so is the wattage and we don't want that, we want that to be stable too.

When using temperature control, all that goes out of the window because the clever electronics in our vaping device use that change in resistance to estimate the temperature of the coil. That's why we use different type of wire, like Nickel (Ni200) Titanium (Ti) or Stainless Steel (SS316), that does change fairly dramatically as it gets hot. The device isn't 'measuring the temperature' at all in reality. What it's measuring is the difference in resistance (the ohms) between a cold coil and one that has been heated up.

Your device isn't very good at temperature control
In a perfect world, every vaping device with a TC function would work really well, no matter if it's an expensive mod or an affordable AIO. Sadly the reality is often something else. How good the temperature control works is largely down to how good the chip set in your device is. Many of the less expansive devices are catching up now but if your mod is a couple of years old and doesn't have a high quality chip set such as Evolv or YiHi then it might not be up to the task.

You have not calibrated your coil at room temperature
For any TC to work correctly everything must be set up at normal room temperature. If you have been heating your coil and it's not working correctly then you need to let the coil completely cool before trying again. This usually means unscrewing the atomiser and waiting for it to cool before reattaching and letting the mod read the coil resistance. Some devices allow you to lock the resistance in this cool state to avoid this happening again. I know this sounds confusing and slightly complicated but in simple terms the resistance showing on your display when you start must be accurate and it can only be accurate when the coil is at a normal unheated state.

The TCR value needs adjusting
Some vaping mods will have an option of inputting your own TCR values to use in temperature control mode or adjusting the values in the presets for different wire types. This is probably more than most people want to get into but it's an acronym for 'temperature coefficient of resistance'. In other words it's what we've been talking about already: 'How much the resistance changes when it's heated'. Different wires have different TCR values, there are even small differences between the various types of Stainless Steel. It's worth checking that your device has the correct value for the wire you are using, because sometimes they are not set to what they should be. A search online should bring up further help in this area if you want to look into this further.

The wattage level isn't high enough
When vaping in temperature control it's important to have the wattage set high enough. On some mods this isn't even adjustable in 'TC Mode' and it just uses the maximum power available. It seems counter intuitive if you've been vaping in power/wattage mode for a long time, but in TC mode we are using the temperature adjustment to control the vaping experience, not the wattage. If the wattage is set too low then it's possible that the coil won't ever reach the temperature you have it set at and give the feeling that nothing is actually happening. The goal when vaping in TC is usually to reach the temperature quickly and have consistent vape throughout the whole puff. If the power is too low it may take several seconds to reach its temperature. On a short puff it might not actually be doing anything other than applying power without any limiting effect taking place. That leads us nicely onto the next point, which is...

Temperature control should actually be called temperature limiting
… or even power limiting, because that's what's happening. Calling it 'Temperature Control' gives us the wrong impression of what's happening and leads to a lot of the confusion around the function. As I stated before the vaping device is reading the change in resistance and what it does is limit the power going to the coil to keep the resistance lower. People have said to me before that when using TC it feels that the power is just dropping off and that's because that is exactly what's happening. In reality is doing very little in the way of 'control', a very similar effect can be achieved on some mods using the 'power curve' mode and just reducing the power slowly after the first few second or two.

Maybe Temperature Control just isn't for you?
I know people that just 'don't like' TC vaping, it feels different when they take a draw and they don't enjoy that difference. While using temperature control can offer some benefits, it's not essential to vaping or to having a great vaping experience. If you are having still having issues and not getting on with this way of vaping then don't get frustrated, just stick to wattage mode, it's worked perfectly well for many of us for a long time.