Geoff wrote:
Should water recirculate thru the header tank ?

No. Definitely not. Never.

I ask as I was up in the loft last night and every time I could hear the boiler
fire up for the heating, what looked like a overflow pipe starting trickeling
hot water into the header tank.

It is pumping over. The waterfall will absorb oxygen from the air and
acrry it into the system where it will corrode the inside of the
radiators.


Is this as it should be or is it yet another problem made for us by the Yeehaa
plumbing company ?

It needs sorting out promptly. If you leave it, it will become new
radiators, powerflushing and still need sorting out. I couldn't suggest
the best way of doing this without examining the installation.