I've had a heat pump dryer for over a year now (non branded, it was from the kitchen supplier).
It take ages to dry anything on a cotton setting (about three hours) - which I understand is common. However, most of the time the washing comes out damp, and needs airing by hanging on an airer which defeats the object somewhat. I've also noticed that the water tank is often empty or has about a teaspoon of water in it when finished.
Is this normal?!