Gotcha like cooking with the lid on it takes less heat to boil sorta like a pressure cooker too?No sorry for the confusion. Because the cover is on when you're boiling you can use a much lower duty cycle on the boil element. On my rig 38% is a very vigorous boil with the cover on. The steam condenser handles that just fine. However, if you raise the duty cycle too high it cannot evacuate all of the steam and it'll pressurize the kettle enough that some steam escapes from the lid.