Belling mod.1000GT oven will not turn off?

By "knob" do you just mean the knob on the front control panel or do you mean the gas valve itself?

Sounds lik ethe gas valve is leaking - one would be tempted to suggest you get a Gas Safe certified engineer to look at it

http://www.buyspares.co.uk/belling/cooker-oven/hob-gas-valve/product.pl?pid=1908964&shop=belling&path=112737&refine=valve

acp
April 2017