vento heater problems

hi, the heater/fan blower in my vento just stopped!! it was stopping and going every 2 or 3 days but finally gave up. when you turn the switch to 2 3 or 4 nothing happens. if its at 1 a small bit of air comes out and you can change from hot to cold, but theres just no power. by the way its an irish vento. any info please reply thanks!!
ciaran