The Hoover heat pump dryer works in a more energy efficient way than a traditional tumble dryer and it is not necessary for it to get really hot inside the drum to dry your clothes. It uses a different technology to achieve a high energy efficiency rating, which not only saves you money but also cares for the fabric of your garments.
It can take up to 30 minutes to feel warm inside the drum. Also check that the dryer is installed in a warm room, they are designed to work in a room that is always warmer than 7 degrees C. During winter months the product will not get hot if it is fitted in your garage or a cold room.
It is perfectly normal for your heat pump dryer not feel hot inside the drum when you open the door.