The gasoline burner flame represents the ultimate challenge: mixing gas and oxygen in just the right amounts to create combustion, giving us controlled heat with minimal light. The simplest and most effective example of this may be the ancient Bunsen burner. This type of burner premixes air and gas before reaching the flame, resulting in a highly efficient flame that burns intensely, but with a clean, smokeless flame. The shape and size of the burner are the two factors that place the flame exactly where direct heat is most needed.
In a toaster or broiler, for example, the gasoline flame is directed at a metal or molded ceramic screen, which heats up to a deep red color and emits infrared heat rays that penetrate the food being cooked. The latest innovation within the industry may be the high consumption gasoline burner, which burns twice as much gasoline (for greater heat intensity) than a conventional burner of the same size. Amazingly, the combination of natural gas and air can produce stovetop temperatures of up to 3,000 degrees Fahrenheit.
One of the functions of the gas appliance is to limit and distribute the available heat, in order to reach the precise temperature to cook food correctly. You will find that a gas burner sometimes makes a hissing or roaring noise when it is turned on. This is known as a flashback, and it occurs because the burning rate is faster than the gas flow. This type of flashback occurs much more often with fast burning gases like propane.
An additional type of flashback occurs when the burner is turned off, creating a popping sound known as an extinguishing pop. Occasionally it is so pronounced that it puts out the pilot flame. You can usually correct both types of flashback by reducing the primary air intake to the burner. If you’re not sure how to do it yourself, remember that burner adjustment is a free service from many gas companies. Flashback is not dangerous, but it is annoying.
It creates soot and carbon monoxide and often means you have to relight your pilot. Inside the burner, repeated occurrences of kickback can cause it to warp or crack. It makes a lot more sense to adjust the burner than to live with flashback. A number of other conditions may need professional attention and adjustment. You may notice that the flames appear to rise and then fall over parts of the burner head at irregular intervals, as if unseen hands are fiddling with the control knob.
This burner can seem a bit loud than the others, making a roaring sound every time the flames get better. Flame lift, as it is sometimes known, is not a normal, stable burner condition and should be corrected immediately. Incomplete combustion can also cause floating flames that appear sluggish and are not shaped like well-defined cones. This is a dangerous situation, and you will usually notice it in the first minute or two after a burner ignites, before you reach the correct airflow.
If the flames do not quickly assume their typical cone shapes, have the burner checked. Finally, the most serious condition is the display of flames. When the burner is lit, the flames shoot out from the firebox opening instead of the top of the burner. Flame throwing is truly a serious fire hazard and must be fixed immediately. The burner may not be positioned correctly or something may have obstructed its internal workings. Either way, call the quick service person.