bleeding radiaters?

The chemical smell is probably something called a 'rust inhibitar' that should be installed when system is initially filled or after say a drain down. Has this particular radiator been cold or off for a while prior to you bleeding it, may be that it's stagnant water has spilt on to radiator whilst you were bleeding it. It may need taken off the wall and flushing out with fresh water (hose).

Bill
March 2011