Thanks rustic. Took car down to a local mechanic yesterday,he confirmed the matrix was leaking so he by-passed it. Well anyway,my daughter used the car in the evening,but reported that she noticed steam and water loss again

I checked it today after work,and noticed that one of the pipes he'd used had a split in it

Anyway,I seem to have sorted it now by using one of the original hoses to the heater,and one of the pipes ha had fitted. Joined them with a piece of metal pipe. Taken it for a spin,temp seems ok.. 80-90. Will check again later,then re-fill with anti-freeze mix in the next few days. She will just have to manage without warm air till she has matrix changed. I'm tempted to try rad-weld or a similar product?
Any of you guys had any success fixing a leaking matrix this way?