internal 2kw convector heater will only blow cold air?

I have a manhattan electric fire suite with in internal 2kw convector heater. it has two settings hot or cold. and two fan speeds.It is 1yr old and has been working normally, but at the moment it will only blow cold air. I have removed the back and checked all connections, these are all fine. The convector has no make or model number on it. Nothing stands out as broken on the convector could you pls give me some ideas, many thanks Gareth