Hob sparks but will not light: gas is not reaching the burner

This is the opposite of the usual ignition complaint. The spark is there. What is missing is gas at the burner, and that has a short list of causes.

First, the safety check

If you smell gas, stop pressing the knob and follow the leak procedure: no switches, windows open, supply off, step out, call. Spark plus gas smell is a leak.

If there is no smell

• Supply: is the wall valve or cylinder open? On PNG, is the meter valve on?
• Knob: are you pushing fully in before turning? The push opens the valve on a hob
• Cap: is the burner cap seated squarely? A crooked cap can block gas from the ports the spark reaches
• Wet: after a spill, water in the burner blocks gas until it dries
• One burner only: the jet for that burner is blocked

If it is every burner

The problem is upstream of the hob — supply valve, regulator, or the connection under the counter. Do not go under the counter to check the gas fittings yourself; that is a leak-test job.

If it is one burner

The jet or the mixing tube for that burner. Clearing a jet involves the gas path and the correct tool. Poking it with a pin enlarges it and changes the flame permanently.

If a burner sparks for a long time before catching, and then lights with a small pop, gas has been collecting in the burner body. Shorten the attempts — press, count to three, release — rather than holding the spark going.

The visit

Jets cleared, mixing tubes checked, supply pressure confirmed, and a leak test at the end. Usually under an hour.