Hi, my name is XXXXX XXXXX I have been in the home improvement and repair field for 20 years. I will be very glad to help you today. You can adjust the amount of fuel by turning the knob to 0 and remove the knob. You will see a flat head screw that adjusts the flame.
Let me know if you have any further questions. I am happy to help and I am online most times.
There is no flat head screw under the knob on the neff , just the shaft of the control with a flat edge to it.
There may be a cover on it, no screw?
Ok sorry, but I have no other suggestions at this time. I will opt out and another expert should help soon. Mike