Extinction Pop happens when Flashback occurs after the burner has been shut off. Although not normally hazardous, the accompanying noise, usually a small “bang”, is enough to startle users and cause them to become alarmed. Again, adjusting the primary air to the burner will solve this problem. If it persists, the service technician will usually check the orifice size and the gas pressure level for correctness. Replacing the entire burner is the next best alternative if all else fails.

As mentioned earlier, a blue flame is produced when the burner gets the right amount of primary air mixed in with gas. This actually indicates that the burner is operating at maximum efficiency. In contrast, when not enough primary air is supplied to the burner, there is incomplete combustion and so the flame will exhibit what’s known as Yellow-Tipping (or Yellow Flames). Yellow Flames do not burn hot enough and so burner efficiency is actually reduced. This condition produces soot which can blacken surfaces that the flames touch (like pots and pans) or even clog a furnace’s flues or exhaust channels. This clogging can add to further incomplete combustion. Yellow-Tipping can be corrected by adjusting the air shutter until a pure blue flame is produced.

It should be noted that when adjusting the flow of primary air to eliminate the problems previously discussed (Lifting Flames, Flashback, or Extinction Pop), the technician needs to closely observe the color of the burner flame so that correcting one problem doesn’t create a new one, in this case, Yellow-Tipping. Likewise, when adjusting the primary air flow to eliminate Yellow-Tipping make sure that it does not cause Lifting Flames, Flashback or Extinction Pop.