If there's no visible flame on a gas burner, it can be challenging to determine if it's turned on or not, especially if the burner doesn't have any indicator lights. However, there are a few methods you can use to check if a gas burner is turned on safely:
Listen for the gas flow: If you turn on the gas burner, you may be able to hear the sound of gas flowing. This is more noticeable in a quiet environment. Put your ear close to the burner area (without getting too close) and listen for any hissing or gas flow sounds.
Feel for heat: If the gas burner is on, it will produce heat, even if there is no visible flame. Be very cautious while doing this, as you don't want to accidentally touch a hot burner. Hold your hand a few inches above the burner to see if you can feel any heat.
Use a gas leak detector: Some gas leak detectors are equipped with sensors that can detect the presence of natural gas. You can use such a detector to check if gas is coming out of the burner even if there is no visible flame.
Check the control knobs: Some gas stoves have knobs that indicate the position of the burner (off, low, medium, high, etc.). Check the position of the knob to see if it corresponds to the burner you're trying to check. However, keep in mind that this doesn't guarantee the burner is on, as someone might have left the knob turned to the "on" position without the flame being lit.
Use a lighter or matchstick (with extreme caution): If you're comfortable doing so, you can use a long-reach lighter or a long matchstick to carefully see if the burner ignites when you hold the flame near the burner's surface. Make sure to keep your face and hands away from the burner and use caution to avoid any accidents.
Remember, safety is of utmost importance when dealing with gas appliances. If you're unsure whether a gas burner is on or if there's a gas leak, it's best to err on the side of caution. Turn off the gas supply to the stove and contact a professional gas technician to inspect the stove and ensure its safe operation. Gas leaks can be dangerous, so it's crucial to take proper precautions and seek professional help when in doubt.