my steam light is flashing green continuously however no steam?

when I switch my iron on and it heats up it initially sounds like its about to draw water for steam but then stops and the green light on the steam is continually flashing. ive flushed the calc section out to remove all scale but that hasn't worked I'm having to use it as an iron without steam as tat heats up and works fine.

Debbie
July 2016