Ariston Washer/Dryer stopped drying

We have an Ariston Washer Dryer AWD 12 S that is about 1 and a half years old. It has worked reasonably well so far but has suddenly stopped drying porperly. It appears to spin round correctly for the drying cycle but doesn't get hot so the clothes don't dry!! Does anyone have any idea what might cause this issue - or what I can look at to diagnose it further

Cheers in Advance

jonathan ps For a while the programe selector knob has every so often gone into a spaz and continually clicked round - As best I can tell this tends to happen on a program that goes straight through from washing to dryer at some point during thr drying cycle (i.e. washing appears to finish correctly) I'm not sure if this mihgt be connected. This problem has not yet occurred when doing a straight drying program

If you lift the lid, by taking the screws out of the back and sliding the lid either forward or backward to release it from the front clips, then check that the heater box on the top of the outer drum isn't clogged with fluff and things. Once you've taken the lid off you'll see where the screws are to remove the heater box (long thin thing with foil wrapped around it) and then make sure it is all clean and clear inside.

If this is OK, then you'll have to test the thermostat that sits on the side of the heater box (best done with a continuity tester or multi-meter on the ohms setting) and see if this is operating properly.

Check all the wiring connections to the heater as well and make sure that none are broken, damages or loose from their holders.

Once you've done these test it should show you where and if the fault is apparent. If none of these check out and the problem is still occurring, then get back with your findings and someone should be able to help with a bit more info' for you.