Tefal steam generator doesn't get hot enough any more?

I have a Tefal steam generator iron about 5 years old, which I brought with me from the UK. Since last week it will only heat up to the temperature setting for synthetics. If I set it to a hotter setting the light goes off (and the iron cools down). This is making it very difficult to iron cottons etc., plus I get a lot of water on the fabric. Can it be repaired, is it worth the repair costs, and if so where in Brisbane can I get it fixed?