beko condensor tumble dryer partially heating?

i have a beko DRCT 70W condensor dryer. i replaced the heating element but only the lower coils glow, this does not dry the clothes.
i replaced the element thinking it was this that was faulty but it is the same problem.
I have taken the back of and checked all the wiring is connected and it all seems ok.
My question is whether all four heating elements are meant to heat up and if so where would the likely fault be?