Have you any pictures of the fridge and heating system ? Post them up on the Workshop section of this site, and maybe some one could steer you in the right direction, if you have run out of gas, and have refilled, you may need to bleed the system through the cooker by lighting the burners for a few mins, sometimes that works, but if you're unsure about gas, best bring it to someone who works with gas, just for safety reasons,