We managed to obtain an oven on Freecycle as attached image.

Problem is it's very hot on the outside, as in too hot to touch for any length of time, including the knobs. So clearly not very efficient and potentially dangerous.

Question is, what is likely to be causing this? Bad design or something broken?

We had an oven that got hot on the outside - due to mice destroying the insulation between the oven and the outer shell, once the insulation was replaced the situation improved

Or damaged hinges so door doesn't fully close? Have seen that where heavy weight put on door

if the knobs are hot, is the heat leaking from the door and rising? if so it sounds like you have a hinge or door seal problem which could just be a matter of adjustment.

We have an Electrolux cooker similar to the one above, but with a halogen hob. The outside gets very hot, including the knobs.

One thing I've noticed is that the fan which circulates air between the outside of the oven & the underside of the hob comes on at strange times. When the oven is running & up to temperature there is an imperceptible air flow from the slots above the oven door (& presumably between the panes of glass in the over door). A few minutes after the oven has been switched off the fan suddenly turns on for 3-4 minutes pumping out huge quantities of hot air. If cooking something in the oven which generates lots of moisture then steam emits from the rear of the cooker where there is no real ventilation gap; again implying the fan which should move air from back to front isn't working when it should.

David