Hi guys,
Just to let you know how it turned out.
Severe coolant loss happened again yesterday after quite a bit of driving. Tracked down to the alloy pipe exiting the engine before heading through the chassis to the radiator. Massive whole in it caused by a rubbing bolt from the fastener around another pipe.
Glad its sorted and is nothing more costly. Temperature and coolant all good again and car running as it should !!.
Cheers Jamie