Hi
Three of the 4 knobs are stuck & are not able to rotate the.Two of them were like this since last year & the third one just stuck since last 2 days.
Gas cooker knobs can sieze due to the grease in the barrel drying out.The only way to fix this is to get a Corgi Engineer to call and regrease the barrels.
Gasman, October 2008
Could they be jammed with the residue of cooking? Have you attempted to clean with soapy water and an old tooth brush? Three down and one to go - it'll be just takeaways soon.