News - Basic Working Principle And Common Fault Judgment Of a Domestic Gas Water Heater

Basic Working Principle And Common Fault Judgment Of a Domestic Gas Water Heater

Most urban households use gas water heaters. Understanding the basic working principles of a gas water heaters and knowledge of common fault judgments will bring a lot of convenience to family life.

Although there are many manufacturers of domestic gas water heaters, many brands and models, and the distinction between petroleum gas and pipeline gas, the basic working principle is the same. Usually, when the hot water tap or shower switch is turned on, the water enters the water heater from the tap, flows through the heating copper pipe to be heated, and then flows out to get hot water. Since gas leakage is very dangerous, there are two gates for the water heater to control the gas, one is a water control valve and the other is a solenoid valve. When the water with sufficient pressure flows through the inner water pipe, the water pressure will push a horizontal bar, the water control valve will be opened, and the gas can pass the first level. At the same time, the horizontal bar will also turn on the main switch of the water control power supply of the lighter, and the lighter will work with electricity, start the ignition, and open the solenoid valve at the same time. The solenoid valve is also opened, and the gas can enter the combustion plate through the second level, and when it encounters a spark, it burns and starts to boil water.

The above is the basic startup process. Usually the most common failure is not burning. When you encounter this problem, you can infer the following ideas:

If the water pressure is normal, but the water pressure of the hot water faucet or shower is abnormal, it may be that the hot water faucet or shower is dirty and blocked. Clean it up and restore the normal water pressure.

If the water pressure at the water outlet is normal, it depends on whether the fire is on. If you can't hear the sound of ignition, first check whether the battery is in poor contact or has no electricity. If there is no problem with the battery, most of the water control power switches are in poor contact. Open the water heater shell, it is easy to see the water control power main switch installed at the lower part of the water heater. It is black plastic, and there is a small iron sheet on the right side pressing a small contact. Press it to close, release it to open. You can use your fingernail to break the small iron piece to the right and release the switch artificially. If it is normal, it will fire immediately. If there is no fire, most of the switch is broken, and the damage rate of this switch is very high. This switch is not expensive, just buy one and replace it.

If you hear the sound of a fire, you need to see if it burns and then goes out, or if there is no movement at all. If it is the former, it means that the solenoid valve is opened for a while, and then closed again, and a small "tek" sound of the solenoid valve opening can generally be heard near the water heater. If it is the latter, the solenoid valve is generally not opened at all, and most of the lighters are broken. Just replace the solenoid valve. Generally, the solenoid valve will not be damaged, that is, the damage rate is low. However, because the inferior water heater uses inferior materials as the solenoid valve lever, it is easy to rust, resulting in poor lever movement, so the solenoid valve cannot be opened. If it burns and then goes out, it means that the lighter can work normally all at once. This phenomenon is related to the energy-saving design of lighters. Anyone who has studied electrical engineering will know that the electromagnet needs a large current when it starts, and only a small maintenance current after starting. The opening of the lighter control solenoid valve has two paths of current, and the solenoid valve also has two sets of working coils. When it is just started, there is generally current flowing out of both circuits, so that the solenoid valve can be opened smoothly. After opening, such a large current is not needed, so the circuit called the starting circuit is turned off. The starting current is generally large, and the solenoid valve can be started alone. Speaking of this, everyone should understand that it should be a problem with the maintenance current if it burns and then goes out. The maintenance circuit is abnormal either because the battery voltage is too low, or there is a problem with the lighter, replace it. Some of the gas water heaters on the market that resist this failure often occur. If you have a knack for electrical repairs, you can also repair lighters yourself.

If it burns normally after encountering boiling water, and the ignition indicator is on at the same time, but the ignition continues, and then the ignition stops after about ten seconds, and the combustion stops at the same time. Generally, there is a problem with the combustion detection circuit of the lighter, most of which are poor contact between the probe and the wire. In order to prevent the gas from entering the burner without burning and overflowing, there is a combustion detection probe next to the burner in addition to two ignition needles. This probe is not made of any special material, but uses the flame to connect with the burner, destroying the oscillation conditions of the high-voltage oscillator inside the lighter, and has the effect of stopping the ignition when the fire starts, which can save energy and at the same time make The holding current is always output to keep the solenoid valve open. If there is no ignition, the internal oscillator timed out, the ignition is stopped, and the solenoid valve is closed.

Post time: Jul-14-2022