I have the same cooker 11-277-10 and like you I believe my oven thermostat is not working.
It lights but does not increase in flame when turned up to the highest gas mark.
have you checked out espares.co.uk?
They seem pretty good though I cannot find the real number that we both seek. The number you quoted in your email was the G.C. # which is visible behind the lower place beneath the oven. I dont think that this is the number they are looking for when trying to match spares. I have exhausted my search in looking for other numbers, I called their 0845 230 6 230 # several times without even an answer and so like you, I am now looking for other alternatives.
Steve Solihull, January 2010
