I can hear really loud constant knocking noises and vibration sounds thought it was pipes but it always sounds worse on a night when the heating is not on but it also sounds like it is coming from chimney anyone any ideas

I am sitting here in my house at 6 am. There is a high wind outside and I hear various noises. One in particular which is quite strange but I know it is the dryer vent flap vibrating from the wind. My husband didn't know what the noise was.

Maybe some of the flashing is loose around your chimney and is reacting from the wind. Hire someone to look if you think that is the cause. Or go up there yourself and explore. Best way to find out.