My Tefal Steam Generator (GV 5140 Easicord) not steaming?

My Tefal Steam Generator (GV 5140 Easicord) is not producing any steam. It heats up and works as a non-steam iron, no problems, but makes no steam noises and does not produce steam.

I had bought it off eBay - a retruned or ex-display product, with no guarantee - in April. Tefal said it would not be cost effective to fix it through them. Does anyone have an idea if there's a component I could try replacing and where would I get it. Alternatively, do you know someone in Sheffield who could try to fix it? Or should I accept my eBay gamble didn't pay off and pay for a new one?