Now this may be coincidence but its worried me. I went to check the fluid levels on the rst tonite. The water is usually at the max line when stone cold but it was about 3 cm above. So I squeezed the hoses to see if they were full of water and in case of an air lock.
Then comes the worrying part. I took the oil cap off and the header tank started 'glugging' and the water level returned to normal. I had a new header tank cap to fit as last time I used it I noticed staining on the header tank where water had come out the cap.

Coincidence as I had just squeezed the pipes or does it indicate the headgaskets gone and the oil and water side are no longer seperate?