If the heat functionality on your tumble dryer is behaving erratically it could be time to replace the thermostats, the other culprit could be the heat element.

This replacement thermostat is for the front position. It's a genuine spare part made to fit the select models of Ariston, Hotpoint and Indesit tumble dryers listed in the list of appliances, so prior to ordering please check the list to ensure compatibility with your particular model.