Hi Alastair,
You have a problem with your cooling capacity.
The red light tells you that the tempreture in your freezer is too warm.
The thermostat knows this and is askiing the compressor to cool it down.
It is not able to, either due to the motor being weak or you may have lost refrigerant gas.
Either way you need an Engineer.
Big Tone The Fridge Man, August 2008
