Not sure if VF same as VS, but should automatically be on once batteries inserted, if not 5 clicks to switch on, 5 clicks to lock it, then whilst locked you press & hold + & - buttons together to enter TC when the actual figure shows 450 or whatever you press the + button and go past 600 to OFF (pressing - will take you down to 200 and then possibly change to °C, my VS is °F only), you can only enter TC/change Temp with the device locked, unlocked the +/- buttons change the wattage. 5 clicks of course to unlock it. Hope that makes sense.
Yes it makes perfect sense bob and thanks



