Sorry I am no expert but the heating element inside may be dead. An electrician or the supplier needs to be contacted. Idealworldtv are advertising them cheap this week. (They usually only sell good quality items, they dropped the price by £20, I think its £39 now and comes with attachements.
More expensive models have a safety cut out as you can imagine, if the water runs out the heater is at risk.
Robert G Kimberley, September 2009