My Hotpoint TDC 62 is not drying fully (but iIS drying partly)?

Hi, Seen the other qu's on here re TDC62's but ours dries it just needs to be run at least twice before getting dry. It beeps to signal the cyle has finishes but the clothes aren't fully dry. We then put it on again and eventually they are. Would this be the thermostat on the drum rather than the trip 'stats? Or are we looking at a heater element or something else? Also the fluff that collects at the front of the condensor seems to be a lot more damp than is used to be if that any help!