Vauxhall Vectra Leak

I Have Just Had A Thermostat Kit Fitted But I Am Loosing Water ( The Radiator Light Is On On The Dashboard )

I Noticed That I Had No Heating But My Temperature Gauge Would Go Through The Roof So I Changed My Thermostat But Still No Heating And Temp...

I Have Recently Started To Lose Quite A Lot Of Water (the Level Falls Around 1 Inch Every Week). This Seems To Happen Even When The Car Is...