Hi Mark
F03 is a propblem with the temperature sensor - also called the thermistor or NTC. Its open or short circuit. Replacement required. Should be located down round the base of the drum at rear. 2 thin wires leading from it. WASHING MACHINE SERVICE AND REPAIR MANUAL.
cut and paste the following address into your browser for more info. www.2ndwave.co.uk/manual.html
dan, February 2008