"Thank you very much Guys. The Mains Heater Element was naff. Found it fairly easy to replace and gave the Gas Jet a clear out at the same time, cheaper than paying for a new fridge - one price I was quoted was ?811.00!!!
I would still like to know how to remove the Mains Thermostat switch thermo coupling from the fridge where it appears to share a channel with the Gas Thermostat switch coupling. Any ideas please?"
"Both thermostat sender tubes fit in channels side by side in the left hand finned heat cold exchanger at the back of the fridge. Several 'torx' screws hold the exchanger and these must be removed to release it, once free it slides down off the thermostat tubes and these can then be straightened out and pulled out from the top of the fridge.
Generally though unless theres a green discharge coming from the tubes their ok."