The portable gasstove can not be switch on or off.
What´s the problem?
If you have got enough clusters free in your inventory (jacket, pants, backback, .....) you can not choose the option "activate" in normaly menue. You can decide between "take it" (to inventory) or "take it in hands" {F1039964}.
When you aim you crosshair a little bit deeper you get an extra option "activate" but it does not works. {F1039966}.
BUT If the clusters in inventory have not enough space for the portable gasstove the option menu will switch to "activate" and "take it in hands". So you can activate the portable gasstove. {F1039969}
NOTICE:
It´s not required that:
a) a pot must be install and
b) the pot was fill with water