Can anyone advise me - my Indesit IDL40 has stopped heating up?

Hi Has anyone else experienced a problem with the Dishwasher stopping heating up? My Indesit IDL40 Dishwasher has stopped heating up. It goes through the wash cycle but the water is cold and when it gets to the drying cycle, the fourth light flashes and nothing happens. Can anyone please offer any advice about how to fix this? It's only 18 months old, and this is the second problem in 2 months - had to replace the upper wash arm last month!
Thanks in anticipation