Thanks for the below.........actually very easily resolved, the dial on the dashboard was kaput, just had to fiddle around at the back and pull the wire manually and hey presto, heat is restored.
Ian
November 2009
You may have a blockage in the heater matrix or even an air lock, try flushing the matrix with a hose pipe and then fill the cooling system as much as you can by removing the top hose from the radiator and then fill the rest from the expansion tank as normal.
Steve
November 2009
Is the engine reaching the correct running temperature, what is the dash guage saying?