I have an AEG Lavatherm Tumble Dryer. It is about 5 years old and i have never had any problems. It has suddenly stopped working, when you press start (on any cycle) it starts up as normal for a few seconds then stops and makes three short beeping sounds and the Start/Pause light flashes amber. The three short beeps then sound again around every 20 seconds. Does anyone know what i should try before calling out an engineer?