There is a great deal of water pouring from a little spout thing off my roof onto my conservatory. It's been going on for about hald an hour and there's seriously an absolutely massive amount of water spurting out. I've had people in the street staring at it and telling me something is very wrong [how helpful!]. It's sort of hosepipe on full blast level.

Does anyone know any potential ways of fixing this without calling a plumber? Or just what the problem might be? I'm not actually convinced our conservatory roof cand withstand the pressure.