Tefal Pro Express GV8430?

My Tefal Pro Express steam generator is switching on but the iron is not heating up, I can hear the sound of the steam as if it's struggling to get the steam through, but when it does eventually it leaks water. I have anti-calced it, it has plenty of water in it and also the programmes are matched up on the iron and the generator. could someone help me I can't do without it especially with a big family I get through my ironong so quickly