Zanussi ZDC37100W

Had this for 3 years used 2/3 times a week. The problem is if I put a load in for 45mins it doesn’t seem to dry as well as it did when it was first bought. When you set it to go again no matter what time the cycle is set for , after less than minute it beeps to say empty water.I then have to leave it a couple of hours before it will run for any length of time. I have cleaned the filters , heat exchanger and wiped the drum with vinegar soaked cloth. Hope you can help.