Indesit vented dryer IS60V has a fault on the ON switch. When you hold it pressed in the dryer turne and heats normally. if you let go , the button ecomes out slightly proud of the fascia and the dryer switches of.. Occasionally it stays on but I can't find out why.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix tumble dryers.