Gas burner clicks and sparks but will not light, or lights and goes out when knob is released.

Safety first: Turn off the burner and allow components to cool. If you smell gas continuously, shut off the gas supply and ventilate the area.

• Clean and align burner: Remove the burner cap and head. Clean all ports with a soft brush and a wooden toothpick (do not enlarge holes). Ensure the cap is correctly seated and centered when refitted.
• Hold knob longer: When lighting, press and hold the knob for 5–10 seconds after ignition to allow the thermocouple to heat. If the flame still goes out when released, the thermocouple or FFD may be faulty.
• Inspect thermocouple: Check that the thermocouple tip is correctly positioned in the flame and not bent away. Light surface cleaning with fine emery paper can improve contact.
• Professional replacement: If cleaning and alignment do not help, a gas engineer should test and replace the thermocouple or FFD valve as needed.

Note: Do not attempt to adjust gas valves yourself unless you are certified.