Well went out to the barge today for a quick trip to Halfords in Swindon. Went to car turned key flat battery, jump started from wifes Astra. Got to halfords didn't have what I was after so started to return home. On pulling onto the A419 dual carriageway put my foot down to get past some slower cars only to look in my rear view mirror to see nothing but white smoke everywhere. The temp gauge read normwl and the car didn't cough os splutter so don't think its a head gasket. Pulled over in local industrial estate smoke still everywhere lifted bonnet to be met by more white smoke and an empty expansion tank. Soon after this a pool of hot water was forming under the car. The leak looks like its coming from the right rear of the engine(rear wheel drive so would be front right on front wheel drive). Had to catch a bus back home to collect the wifes Astra to tow the poor old barge back home.
Will be doing some diagnostic work on it tomorrow, hopefully just a burst hose.