What is the reason why the gas water heater makes abnormal noise when it is turned on?

When the gas water heater is turned on, the abnormal clicking sound may be caused by the following reasons:

The local aging of the high-voltage line of gas water heater leads to the internal core wire being exposed, resulting in high-voltage discharge with the shell. The high-voltage output end of the pulse igniter is connected with a high-voltage capacitor, and the high-voltage capacitor converts the pulse alternating current into a high-voltage DC output. Because the interval between charging and discharging of the capacitor is short, the sound is intermittent.

The high-voltage coil in the high-voltage pulse igniter of gas water heater has local ignition and discharge phenomenon, which is mostly caused by humidity or quality problems, resulting in the decline of insulation performance, and it will make a snapping sound when high-voltage discharge occurs;

When there is a problem with the water-gas linkage valve of the gas water heater, although the water is turned off, the gas thimble is not reset in time, resulting in the continuous output of gas for a short time. At this time, the high temperature will make the water tank change instantly between cold and hot because the flame continues to burn after the water is cut off, resulting in the phenomenon of thermal expansion and cold contraction, thus making an abnormal snapping sound, which is particularly loud and has a sharp tail sound.

Corresponding solutions to the above faults:

After disassembling the machine, carefully check the high voltage output line of the pulse igniter for local aging or damage. If yes, it shall be bonded with high-voltage insulating tape in time and covered with fireproof and high-temperature resistant insulating tube.

Check the pulse ignition module, take off its cover, and you will see two high-voltage coils inside. Start the test to see if the coil is ignited and discharged. It is best to dim the surrounding light for easy observation. In case of ignition, a new pulse ignition assembly should be replaced in time;

When in use, observe whether the flame of the water heater disappears immediately after turning off the water. If it doesn't disappear immediately, replace the air valve ejector pin of the water-gas linkage valve, and directly replace the whole water-gas linkage valve if possible to avoid the failure from happening again.

Note: Gas water heaters are as dangerous as gas stoves. If there is any fault, please ask professional maintenance personnel to repair it in time to avoid the fault expansion caused by immature technology.