system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why is it necessary to leave the door of the oven open when using the grill ?

I never understood this, surely the oven is designed for high temps so why the need to leave the door open?
gpt
You only leave it a little open (~5cm - the door will stay in position) ,  this is to stop the oven from reaching temp and cycling off the element. This means you get a continuous hot heat on whatever you're grilling.
If you're fan-grilling then you keep the door shut.