Lack of steam

I have recently bought this item secondhand. There is water in the steamer, but I cannot get the steam to come out of the end of the nozzle. How long does it take for the water to heat. I have only tried using it when one of the lights go out. I just don't seem to be able to get anhything else other than a drip out of it. Am I not waiting long enough for the water to turn to steam?