Then many friends asked, why are there two ceramic ignition needles? One ignition needle cannot be used. I think there is one needle in the burner of the gas stove? In fact, everyone is right, but the gas The fire row inside the water heater is very different from the gas stove. If the precision control of the gas water heater is good, it can also achieve a single needle ignition, and the distance between the ignition needle and the fire row is controlled within 4-6mm.
When we turn on the hot water faucet, the water flow sensor starts to work. After the single chip detects the water flow signal, it outputs a signal to the pulse igniter. The pulse igniter generates high voltage and discharges the arc through the tip of the ignition needle. If the distance is too far or too close, the ignition will not be successful. Therefore, in order to avoid the error, let the ignition needle discharge at the tip and the receiving needle next to the arc to ignite, so that they are connected together and fixed on the fire row, reducing the error, thus forming a double needle ignition. So what we see is one is pointed and the other is flat.
![](/ymceramic/2021/08/31/wire-wound-resistor-ceramics-1.jpg?imageView2/2/format/jp2)
![](/ymceramic/2021/08/31/wire-wound-resistor-ceramics-1.jpg?imageView2/2/format/jp2)
The induction needle is easy to understand. In fact, it is exactly the same as the induction needle of a gas stove. The induction needle of a gas stove can be divided into a thermocouple and an ion induction needle, and the gas water heater is basically an ion induction needle. We can see that its needle body is very long. When the flame burns, the needle body is burned by the flame, and the flame can generate unidirectional conductive ions, which can be sensed by the pulse igniter.
Therefore, the function of the pulse igniter is that when the tip discharge ignition is successful, the ion needle is burned at this time, and after the pulse igniter detects it, it will no longer discharge and ignite. At the same time, if the flame is turned off in the middle, the microcontroller will issue an instruction to close the gas proportional valve to avoid accidents, so this is why the ceramic ignition needle and the induction needle cannot be exchanged.