Vented tumble dryer very hot?

longwalks1

We have a vented, White Knight tumble dryer, it’s about 3 years old. Gets used maybe 3 times a week, even through the summer months.
Tonight we got a couple of bits out of it and the clothes were almost too hot to touch, as was the front of the machine (where the controls are)
We clean the fluff from the slide-in filter every single time (I’m a bit OCD with it), any ideas what it could be please? I’ve never noticed how hot it gets previously hence me asking

Nilrem

There could be a blockage in the outlet pipe or external vent.

I would have a look at the vent (if possible, not so easy if it's in a 3rd floor flat;)), as ours used to get quite clogged up every couple of years because the filters on the average tumble dryer (including the replacement Hotpoint we got) tend to still let fluff past them.
Not as much as without the filters, but enough that over time it can/will build up in the vent pipes and catch on the inside of the vent flaps causing a restricted airflow and additional heating in the dryer (as they tend to control the heat simply by airflow over a heating element that is either fully on, or only half on so reduced airflow means it gets hotter).