wont be thermo couple,that only keeps the gas flowing when you let go of the valve.if gas has been replaced there maybe air in the pipes or check the pressure regulator on the gas bottle,replace it if in doubt,also check for a on/off tap,usually under a unit near the fridge,they tend to get turned off in winter,failing that remove fridge and clean out the jet,easy enough to do ,takes an hour or so to do.
mikec
July 2010