Hi Bob, It is APM 6325.
The thermostat control knob it at the top.
I thought there might be access by taking the light out but it doesn’t seem big enough.
Thanks for the help Bob, I will let you know how I get on. Unfortunately the fridge is locked in by the cupboard its in, the work surface above and kick board which is also fixed by being tiled up-to after the fridge and cupboards were fitted.