The fogger will only operate as long as the heat-exchanger is hot enough to vaporize the fog juice. The initial warm-up time is dedicated to this task.
But as soon as you press the button, generating fog, that heat is used up, and the heat exchanger cools down. If you have a low-wattage machine, a good long fog burst will cool the machine enough that it will have to stop and reheat.
Non-commercial grade glycol foggers are generally not capable of continuous fogging.
