First of all let me say I take no credit for finding these methods - I have merely verified they actually work and collected them all together in one place to stop a lot of searching by others experiencing this strange phenomena.
It seems whenever you remove a device from the top of the Pegasus to fit a different one or to clean and refill etc. then it insists on doing its 30 watt test routine which many people have found can scorch the cotton in their coils, or worse.
There are 3 methods to get around this - at the moment?
1) Lock the device (5 clicks) - remove tank, fit same or another tank- then unlock device (5 clicks) - then set your watts and vape
2) Remove tank, fit same or another tank- give the fire button a brief click (you will see the voltage hit 7+ volts probably) - THEN WAIT for the display to switch off - then set your watts and vape
3) Remove the battery - install your tank - insert the battery and as you close the battery door and the "ASPIRE" legend appears on screen press and hold the fire button - wait for the screen to blank then release the fire button - then set your watts and vape
Please note these have only been tested in normal wattage mode