This excerpt from the user's manual can explain the problem of your filter.
"... Open the loading door and set the "Ready to wear" level and stay lit until the laundry is delivered. C Make sure that the air vents are "Fine/Anti-Crease": open, that the door filter is cleaned - Lights up when the programme is finished and the water tank is empty. The heat exchanger filter is clogged. Ironing creates creases after the ProSteam programme. Clean the heat exchanger filter...."
WHIRLPOOL AWZ 9578, HOOVER VHC 381 XT, SAMSUNG DV90K6000CW, DV90K6000CW/ET, , AEG T75782NIH, 916 097 769, BOSCH WTN83280, LG DLEY1201V, HOOVER HLE C9TCE, HLE C9TCE
Manufacturer's part price is £40.83 Discount for bulk (starting at 10 units), £39.48 per unit
This manufacturer part is recomended by HOOVER, which gives it a 10/10 rating.
This spare part is recommended for your HOOVER HLE C9TCE dryer .
All spare parts are new and come with two years warranty
① Carefully check your HOOVER dryer's product number
② Start search
Here are examples for partial reference for dryer :
Where to find the reference?