What to do if the gas valve on the gas column does not work: features of diagnostics and repair

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Victor Kitaev
Last update: August 2019

In case of any breakdown, most owners of the gas column call the master of a specialized service. However, services are usually accompanied by financial costs, right?

Why not independently solve a seemingly insignificant problem, having the skills of a mechanic? With a situation when the gas valve on the gas column does not work, you can try to cope on your own. But what is needed for this and where to start?

In this article we will talk about the design features of the gas valve. We will analyze the main failures leading to the inoperability of the column. For a better understanding of the process of diagnosis and disassembly, we will provide the presented material with visual photographs and a video.

Geyser valve device

In order to make it easier for home masters to restore the functionality of a gas boiler, in particular when a malfunction of the gas valve is noted, we will consider the assembly of the unit and the technical nuances of diagnosis and repair.

But, if you do not have experience in disassembling geysers and relevant knowledge on the topic, then for repair and maintenance preferably invite the master.

The device, called the gas solenoid valve, performs an important function of the gas column - control the flow of the fuel component (natural gas). The picture below shows a common version of the design of the control unit, which includes the valve.

Geyser solenoid valve
The appearance of the unit that performs the function of adjusting the gas supply to the gas burner system of the boiler (column). The device contains an electromagnetic gas valve (1), a manual stem (2)

In fact, the control unit is a two-stage mechanism, the first stage of which is precisely the gas solenoid valve (1).The second stage is a mechanical device that provides adjustment by means of a manual control rod (2).

The design of the gas valve is quite simple - it is made according to the principle of an electromagnetic traction device, which are used as part of a wide variety of devices and devices. If you dismantle this component from the circuit of the control unit, for which it is enough to unscrew a couple of screws, the valve part will appear before the eyes of the master, which is mounted on a spring-loaded metal rod.

Dismantling the gas boiler valve (disassembly)
This is what the inside of the device looks like (in fact, the valve itself), after dismantling the gas valve from the control unit of the column (boiler)

As you can see in the picture, the design consists of skirtswhere the valve part enters - membrane and electromagnetic module. The valve part is mounted on a metal stockspring-loaded for the return stroke to the closed position.

When voltage is applied to the coil of the electromagnet, the metal rod moves upward under magnetic action and diverts the membrane from the passage opening of the skirt. This opens the gas passage towards the manual valve and further to the burner.

Valve troubleshooting

The loss of efficiency of the gas valve leads to the complete impossibility of operating the heating equipment, or to a situation where the required level of heating is not provided due to incomplete opening of the membrane.

On the other hand, there are possible reasons, on the contrary, leading to a constant flow of gas to the burner of the boiler (column). That is, a situation arises when the gas valve is constantly open.

Stage # 1 - Simple Electrical Component Inspection

It is permissible to test the performance of the gas solenoid valve on the column (boiler) without dismantling the control device. However, to carry out the test directly on the equipment, it is necessary to ensure that the gas supply is turned off by closing the valve on the line. In this case, the geyser (boiler) remains connected to the electrical network.

Microswitch for gas flow regulation
Microswitch installed on the gas flow control device. This component of the circuit switches the supply voltage supplied to the basic elements, including the electromagnetic gas valve

As a rule, an electronic component is present on the device for regulating the gas supply to the burner - a micro switch (see the picture above), by which, when the gas column is turned on, power is supplied to the main technological parts.

In particular, the supply voltage through the micro-switch is supplied:

  • to the ignition module;
  • to the fan of the traction turbine;
  • to the coil of the solenoid valve.

So, if it is forced, for example, with a screwdriver blade, to act on the pusher plate of the microswitch, these gas column systems (boilers) will receive power.

As a result, the following components are activated:

  • a fan;
  • electric lighters;
  • solenoid valve.

That is, the tester will hear the sound of a running fan, the characteristic clicking sounds of a gas lighter, and, of course, the characteristic click of the solenoid valve stem. This condition of the equipment demonstrates the health of the components, in any case - electrical.

Stage # 2 - valve disassembly and testing

The cause of inoperability of the unit may be various defects.

Among them:

  • violation of the shape of the membrane seal;
  • getting into the skirt body of a foreign object;
  • fracture (wedge) of the return spring;
  • break in the conductor of an electromagnet coil.

The first three defects of the list are detected after disassembling the device with a careful inspection of the structure and checking the rod for free axial movement.

Checking the stroke of the gas valve
The loose fit of the membrane seal to the skirt plate and the ease of stroke are the primary testing steps after disassembling the mechanism

A separate approach to testing requires the last item on the list - coil conductor break electromagnet. We will discuss further the types of breakdowns and methods for their elimination.

Stage # 3 - check the electromagnet coil and its repair

The practice of operating gas water heaters and boilers shows that a defect in an electromagnet coil is not only a break in a winding conductor.

Cases are common interturn circuit, which also leads to a loss of operability of the node. How to check the solenoid valve of a household gas column at home?

Checking the valve coil with a tester
Testing any inductor with a tester is a common practice for repair practice. Accordingly, the coil of the gas solenoid valve is also checked for open or inter-turn short circuit using this device

Of course, each individual gas water heater manufacturer (boilers) original valve designs are used. Therefore, the resistances of the inductors included in the electromagnet are significantly different.

In general, one can note a certain range of resistances characteristic of such inductances: 1.3 - 7.5 kOhm. In fact, a specific parameter should indicated in equipment documentation.

The measurement of the inductor is traditionally carried out in the resistance measurement mode - by connecting the tester probes to the contacts of the inductor. If the device does not respond to the connection, it is obvious that there is an open circuit.

If the measured resistance parameter differs from that indicated in the documentation, most likely there is an interturn circuit. In both cases, the coil should be replaced.

Resistance of coils of the gas valve of the Baxi boiler
The picture shows the resistance of the working (serviceable) coils of the gas valves of Baxi boilers, in particular, devices of the SIT SIGMA 845078 series

In practice, replacing a coil as a separate valve element in a gas boiler is rare. As a rule, if it is a failure of the inductance coil that is detected, the masters completely change the solenoid valve assembly.

This replacement is due to the complexity of the search for a specific component. Yes, and the procedure for replacing an individual element is more complicated compared to replacing a gas solenoid valve assembly.

Stage # 4 - troubleshooting mechanical defects

As noted above, a solenoid valve for a household gas water heater may lose functionality for purely mechanical reasons. For example, the accidental appearance of a foreign element inside the valve threatens with a loss of tightness of the membrane seal.

To find the cause of the breakdown, the wizard has to perform a series of actions:

  • remove the gas valve;
  • its subsequent disassembly;
  • attentive check.

These manipulations can detect and eliminate the malfunction associated with the ingress of foreign objects into the working chamber.

Checking the gas valve skirt plate
Visual inspection of the surfaces of the landing plate of the valve skirt reveals the reasons for insufficient sealing of the seal in the mode of closing the gas flow on the column

Among mechanical defects, a fairly common moment is elastic membrane defectwhen there is a violation of the form or partial destruction of the landing site. Here, in principle, you can get by installing a new membrane on the stem, but traditionally masters in such cases resort to a complete replacement of the electromagnetic valve.

A similar situation with device repair when it comes to return spring or loss of necessary pressure by this element. To replace the spring, you have to disassemble the entire structure.

However, some valve models are assembled using a screwless joint - rivet method or metal clips. Therefore, it is much easier to replace the design completely than to engage in restoration.

Stage # 5 - valve assembly and leak test

If the troubleshooting of the gas solenoid valve was accompanied by disassembly of the mechanical structure, reassembly should include careful leak test. Be sure to check gasket integritymounted on the upper rim of the skirt; if necessary, replace the gasket.

Gas valve skirt gasket
Gasket on the side of the skirt. This element should be paid increased attention to during assembly of the structure, since the gasket is often damaged during disassembly

The assembled unit is checked in a standard (traditional) way with the gas supply turned on. A suitable container is taken, where a little water is poured and soap powder is added. Is being created thick soapy foam, which is applied to the skirt body in the place where the gasket is installed. If bubble formation is not visually observed, then tightness is within normal limits.

You figured out the valve, but faced with attenuation of the gas column or other problems? We recommend that you familiarize yourself with our other articles in which we examined the most common breakdowns and how to eliminate them:

Conclusions and useful video on the topic

Testing the device in a simple way, filmed on video, clearly demonstrates how this process is conducted. Of course, such a technique is not suitable for all gas columns without exception, but for most models the material is quite relevant:

The performance test and the operability of the electromagnetic gas valve can be done by yourself or consult a specialist. However, it is worth remembering that gas equipment refers to high-level hazard equipment, and when handling it, certain rules and regulations. The slightest flaws, omissions, ignorance when performing installation (repair) work can lead to serious consequences.

At the same time, an appeal to specialists nullifies the risk component. Therefore, having no experience in performing repairs and relevant knowledge, it is not recommended to compare the cash costs and personal safety in such matters. It’s easier and safer to call the wizard of the specialized service with which you have contract signed.

Do you want to supplement the above material with useful tips for troubleshooting the solenoid valve of gas equipment? Or are you doing independent diagnostics and disassembling the node and want to clarify a couple of nuances? Ask your questions, add unique photos containing a good example, write recommendations in the feedback block located below the article.

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