Gas boiler repair: an overview of common failures and how to fix them

Gas equipment is the most common option in the organization of autonomous heating. It is characterized by reasonable cost, economical fuel consumption and high efficiency. However, any equipment has its own life and requires restoration over time.

The simplest repair of a gas boiler can be carried out personally. And with the implementation of regular preventive measures, any owner is simply obliged to cope independently. We will tell you how to return the equipment to working capacity and how to extend its working life.

What can be repaired without gas workers?

There are several main causes of malfunctions. This is improper operation of gas equipment, the presence of an unacceptable microclimate in the boiler room, untimely maintenance of all systems or low-quality components.

For self-repair, be sure to observe safety precautions and strictly follow the instructions. First of all, the user should decide which parts of the gas boiler can and cannot be repaired independently.

During the repair of gas equipment, the main danger is a possible gas leak. Therefore, it is necessary to carefully carry out all manipulations on mounting and dismantling the units and parts of the device. Particular attention should be paid to the replacement of components associated with the fuel supply system.

Knowledge of typical malfunctions of gas boilers and methods for their elimination allows you to make simple repairs yourself. It is worth remembering that serious repair can only be done by gas workers, but there are procedures available to independent home masters

Boiler manufacturers urge gas service employees to correct problems related to breakdowns in the gas supply system and on-board electronic devices.An inexperienced person will not be able to independently configure, repair and restore the functions of specific automation in a gas boiler.

The design of a typical gas boiler has three main elements, these are:

• Gas burner closed / open type;
• Specific safety blocks;
• A heat exchange system consisting of one or two internal devices, the number of which is determined by the number of serviced circuits.

If all the components involved in the operation of the boiler are classified according to their functional purpose, then they can be divided into the following groups: control system devices, hydraulic system devices, burner and gas supply unit, chimney, boiler control devices, multi-level safety systems.

Most often, users have problems of the following nature: the boiler emits an unpleasant smell of gas, does not turn on, turns off during operation, does not heat pipes or smokes

Most of the listed items cannot be changed and repaired by yourself. In case of interference with the boiler design, its owner loses the right to restore working capacity at the expense of the manufacturer during the warranty period. But what and how do the masters from the organization with which they are concluded repair service contract unit and gas supply, you need to know.

However, the owner of the gas equipment, seeking to extend its service life, can independently produce:

• Chimney cleaning. It is produced in cases of traction weakening by mechanical manipulations or with the use of chemical agents.
• Checking the tightness of the water supply connection points, gas supply lines, heating circuit branches.
• Installation voltage stabilizer.

We warn again that all actions for which it is necessary to remove the casing from the boiler must be performed by a representative of the gas service.

However, if the guarantee is not important for you, then you can do it yourself:

• Manual external cleaning and internal flushing of the heat exchanger / heat exchangers. They are easy to dismantle, carry out the necessary procedures, and then install them back. In this case, it is effective to use homemade aqueous solutions of citric acid (100g / 1l) or suitable household chemicals that can dissolve calcium plaque.
• Service fan boost. Replace the fuse or the fan itself, check the electrical circuit connected to it, lubricate the bearings with technical fluid.
• Nozzle cleaning. Clogged nozzles cause a low burner flame. They periodically need to be cleaned with no fine sandpaper and remove contamination with rags and household chemicals.
• Adjustment of pressure in the system.
• Search for a problem due to which the boiler does not turn on.

In order to determine how and how to fix a gas boiler, it is necessary to carry out a visual inspection and, if necessary, conduct a series of diagnostic procedures. Self-repair is possible in cases where the warranty from the manufacturer has already expired.

If you smell gas, you should immediately forget about your own intervention. It is necessary to shut off the gas supply, immediately carry out volley airing and call an emergency gang. Details of the operation of gas equipment are set out in next article, the content of which we strongly recommend that you read.

Self Diagnostic Methods

Often the user is in a situation where he is not sure what exactly broke in the gas boiler. In such cases, there is no need to rush something to remove and repair. This is risky and dangerous. Before work, you should diagnose the equipment and identify the exact causes of the malfunctions.

If the boiler smokes, then usually the cause of this phenomenon is the consumption of low-quality gas or lack of air.You can check the cause of the malfunction yourself

Modern gas boilers are equipped various sensors, which reflect a number of important functional indicators of the unit. They track changes in temperature, pressure and other parameters. In the event of a malfunction in modern boiler models, an automatic shutdown of the device is provided.

The source of failure is identified by the consequences it causes. For example, visually you can see a burnout, smudges, sparks. You can sense a gas leak or short circuit by smell. By the changed sound of the gas boiler, it becomes clear that the unit has malfunctioned.

The instructions that came with the purchase of the device describe the most common malfunctions in the purchased boiler model and how to detect, diagnose, and eliminate them. It also indicates what a specific error code and flashing lights on the dashboard.

So the light can flash in different modes: fast or slow. Or burn constantly. The color of the light bulb can be red, green or yellow.

The manufacturer's instructions indicate all possible error codes that may appear on the display. However, it also explains how to troubleshoot.

Do not throw the instruction away from the device, as it may come in handy for the gasman you called to correct the breakdown. It indicates the characteristic features of the model of a gas boiler, the size and location of components and parts.

Major malfunctions and their elimination

After carrying out diagnostic procedures and identifying a specific problem, you need to start solving it. To do this, depending on the situation, you will need some tool and accessories. Most problems are easily fixed with a tool that is always at hand.

Before starting work, it is important to disconnect the gas boiler from the electrical network. It is also necessary to shut off the gas supply by turning off the gas valve. Even in cases where repair procedures do not affect parts in contact with gas, it is necessary to turn off the fuel supply in accordance with safety regulations.

Volatile boilers quite often break due to power surges. As a result, not only the settings are reset, but sensitive sensors also become unusable.

In some cases, it is not possible to roughly estimate the duration of the required repair work. If in such a situation the temperature in the street is minus, then a significant decrease in the temperature in the room is possible. And therefore, the water in the system will freeze.

To prevent the appearance of ice plugs in the boiler coils, the anti-icing system is never turned off for a long time. For example, if the boiler is not used for one or two days, all volatile devices are turned off, except for this function. Completely disconnect it from the power supply can only be in the case of conservation of the unit for a long time.

Also, before you start repairing the boiler and dismantling its internal components, you need to make sure that the working surface of the device has an acceptable temperature. During operation, the casing and appliances of the boiler heats up significantly, and contact with some parts can cause burns.

The gas boiler does not turn on

Sometimes when you try to turn on the boiler, it is discovered that the device simply refuses to work. First of all, make sure that the device is connected to the mains. Then you need to check if the switch is on in the dispenser.

If, after inserting the boiler plug into the socket and turning it on, the machine knocks out, then unplug the plug from the socket. Then you need to inspect the wiring for malfunctions.

If it turned out that the device is connected to a working outlet, but still does not start, then you need to disconnect the boiler from the network and carefully remove its protective cover.It is necessary to carefully examine the internal elements of the boiler for signs of a short circuit. These signs include the presence of a burning smell and soot on the internal elements.

If there are no signs of a short circuit, then you need to inspect the fuse and electronic circuit board. In case of detection of a burnt fuse, you need to install a new one, turn on the boiler and check its performance. Sometimes after replacing a new fuse immediately blows. This usually indicates a serious breakdown inside the boiler or problems with wiring.

A common problem with an electronic board is getting it wet. It is better to dry it with an ordinary home hairdryer, and then leave it for a couple of days until the final evaporation of moisture.

The electrical wiring must be checked for proper connection and wiring. You need to make sure that there are no bare wires, short circuits.

If the fuse is found to be in order, inspect the varistor. This device protects the boiler from power surges. Perhaps earlier there was a serious power surge and the varistor exploded. Only a small part of it can remain. To solve this problem, you need to solder the varistor with a blowtorch and the right material.

A varistor is a semiconductor resistor. If the voltage rises to a too high level, then it redirects it through itself, thereby protecting the device

In cases where the boiler is accurately connected to the electrical network, and the fuse and varistor in good order and after inspection could not find the visible causes of problems with starting, you should call the master for repairing gas boilers. Most likely there is a serious internal malfunction, which will be problematic to eliminate at home.

A number of models of gas boilers in which the display is provided error code on the dashboard, they do not turn on and do not give an error code at the same time. Such a problem often manifests itself when the circuit of the temperature sensor installed in the room or on the street is broken.

It is necessary to inspect the room sensor, perhaps it is turned off from the outlet or the batteries are low on it. Then you need to replace the batteries or insert the plug into the outlet. If the temperature is not shown on the boiler panel, then most likely there is a problem with the thermostat and it is advisable to start searching for the problem with it.

Filter and pump problems

The boiler may malfunction due to a clogged cold water filter. To clean it, shut off the water supply and pull out the filter screen. Rinse it under a stream of water or replace with a new one.

The rough filter of the water supply system provides reliable protection of the boiler system from large foreign particles. If contaminated water flows through the water supply, the filter is often clogged

Boiler users may also encounter a problem with the pump. The pump stops pumping water when the rotor is broken or air accumulates inside it. First of all, the health of the rotor is checked. To do this, unscrew the nut from the pump and drain the water. Then you need to insert a flat screwdriver into the slot and force the axis to scroll. Sometimes the pump sticks or sticks.

If it turns out that the pump is broken, then you will need to disassemble it yourself, find out the cause of the breakdown. Having determined which part is broken, you need to order it in a store with gas equipment or from the seller of the boiler. Parts of the pump change at home or in the workshop.

If air has accumulated in the pump, it is necessary to open the air outlet and wait until excess air comes out. The air vent closes with a tight-fitting cap. The air release process is accompanied by a characteristic sound.

The pump is often installed during the heating system in private homes.It allows you to drive warm water in a closed loop and provides the same heating of all radiators

If the gauge needle is in close proximity to the red zone, it is necessary to turn on the boiler and heat the water in the system. If with small heating the pressure rises strongly in the range from 0.7 to 1.5 bar, then you need to carry out the procedure to add air to the expansion tank.

Adding air is carried out after depressurizing the system to zero. This is done by opening the tap and draining the water. Then, using a pump or compressor, the pressure in the tank is pumped up to 1.3 bar. After that, you need to bring the pressure in the system to 1.5 bar.

Heat exchanger cleaning procedure

The cause of the boiler overheating is often faulty automation or a clogged heat exchanger. If gas boiler automation most likely you will have to repair it in the service, then the heat exchanger can be cleaned of clogs at home. To do this, turn off the boiler and wait until it cools down. Turn off all taps and remove the device cover.

With a plastic film, you need to tightly close all electrical components and parts, the pump and control devices so that water does not accidentally get on them. By opening the tap or valve of the gas boiler, the remaining water must be drained from it.

Next, you need to dismantle the burner block with the collector, remove the fan from the seat, disconnecting the fasteners that fix it on the combustion chamber. Then the return pipe is disconnected from the heat exchanger.

Water is heated unevenly due to a violation of thermal conductivity. This is due to the accumulation of a large layer of scale on the walls of the heat exchanger. Uneven heating causes the water to alternate at different temperatures

To remove the heat exchanger, you must first disconnect the overheating sensor, then the combustion chamber is removed. For this, three self-tapping screws are pre-twisted, after which the camera, together with the cap, is pulled onto itself. After that, the cap is detached from the chamber and the heat exchanger is disconnected.

The heat exchanger itself is first mechanically cleaned with a brush and an emery cloth. Then you need to hold the item in a 10% solution of citric acid or household chemicals that dissolve mineral deposits. Soaking in the solution should pour for about 10-15 minutes.

Next, the solution is poured into the internal pipeline and hold it there for a similar period. After everything is drained and thoroughly washed with running water. Assemble in the exact reverse order. In order not to forget the sequence, it is recommended to take a photo of each step on the phone during dismantling.

If you first familiarize yourself with the recommendations for cleaning the heat exchanger and the instructions for disassembling the gas boiler, the preventive cleaning process will not take much time

It is recommended to clean the heat exchanger every one and a half or two years.

The solution to the problem of poor traction

Boilers with an open combustion chamber sometimes lose traction. To determine the cause of this malfunction, it is worth looking directly into the combustion chamber. Perhaps she clogged with soot, soot or decay products. It is necessary to brush and blow this part with a vacuum cleaner.

Models with a closed combustion chamber equip coaxial chimneyswhich have the following disadvantages. In cold winter time, from the outer pipe, water drops fall into the inner one, and there the water freezes and turns into an icicle.

The ice in the space between the pipes blocks the access of air to the gas boiler and, consequently, the flow of fresh air required for combustion is reduced. To solve this problem, the street part of the chimney is insulated or holes are drilled in the outer pipe to drain condensate.

There are situations when foreign objects or waste get into the chimney.In such cases, you need to carefully dismantle the pipe and clean it from excess contents. Malfunctions in the operation of the gas boiler occur when the coaxial chimney is excessively clogged. Soot needs to be cleaned with a certain periodicity. Then the boiler will work long and efficiently.

It is worth noting that the accumulation of soot in a gas boiler is a rather rare occurrence. Gas during combustion does not emit too much burning. Therefore, the manufacturer usually recommends cleaning the chimney once every two or three years.

A pipe cleaning brush is fairly easy to make on your own. However, it can also be purchased at a reasonable price in the store.

The chimney is cleaned as follows. It is necessary to turn off the boiler, shut off the gas and water supply and wait until it cools down. Remove external boiler protection and disconnect from it chimney. Cleaning can be carried out mechanically or chemically.

It is convenient to clean the lower part of the chimney pipe directly adjacent to the boiler with a metal brush with a long handle, and then use a brush. After that, you can use chemical solutions. After cleaning the inside, proceed to clean the outside of the pipe.

You can clean the chimney with your own hands on the roof in several ways. Most often, they use a special metal brush on a rope with a weight attached to it. The circumference of the cleaning tool should correspond to the circumference of the chimney.

Alternately lowering and raising the mechanism, the walls of the pipe are cleaned. Soot falls down and needs to be pulled out, removed or vacuum cleaned from the inside of the chimney.

Also clean the chimney You can use a powerful vacuum cleaner specifically designed for similar procedures. Such a device has pockets for drawing in waste. And the hose has a length sufficient to clean the entire chimney.

In special cases, it is worth calling a chimney sweep, which has a vacuum unit designed for cleaning chimneys. This expensive device will completely clean the chimney from contamination and at the same time will not damage the system.

When cleaning the chimney and other elements of the boiler, you must always wear a mask on your face. It will protect the wearer from inhaling soot and harmful trace elements entering the lungs.

If you do not solve the problem of weak traction in a timely manner, then you can encounter a number of negative consequences:

• Carbon monoxide entering the premises and causing harm to the health of residents;
• Accumulations of soot increase the risk of fire;
• Due to soot on the walls of the boiler, heat loss and gas consumption increase.

Possible problems indicate that regular preventative cleaning of the gas device is necessary.

Replacement of components and elimination of leaks

If leaks and water leaks are detected at the gas boiler connection points, the water supply should be shut off. Then, using a wrench, you need to unscrew the connection, remove the remains of the tow and check the thread for damage. Then you need to apply a new layer of tow or FUM tape and tighten the pipes tightly.

If the inspection reveals that the water pipe is damaged, then you need to replace it yourself or call the plumbing.

The use of FUM tape, plumbing thread, liquid or anaerobic sealant protects pipe joints from leaks. Before re-screwing the pipes, thoroughly clean the threads from foreign elements

If you smell gas in the air, you must turn off the light and all sources of fire. Open the window and ventilate the room. Check for leaks with a soap solution. After applying it to the pipe, a soap bubble appears. A gas leak is eliminated in the same way as on a water pipe.

Sometimes after diagnostics it turns out that it is necessary to replace the burner in a gas boiler. You can replace the burner yourself, but it is worth installing the exact same burner model. It is necessary to disconnect all communications, and when dismantling it is imperative to remember the correct location of all elements connected to the burner.

If the boiler refuses to maintain the set temperature, then a broken sensor is usually to blame. Temperature sensors can be overhead or immersion. Overheads are easily mounted on pipes and replaced without difficulty. When installing an immersion sensor, drain the water from the boiler and, after installing the sensor, seal the threads.

In order to maximally secure your own space and eliminate the possibility of excess toxins due to the operation of gas equipment, it is recommended to use the house carbon monoxide sensor. The principle of its operation, the rules of selection and installation are described in the article we recommend.

Conclusions and useful video on the topic

How to flush the heat exchanger of a gas boiler:

Gas boiler fault detection and correction:

Gas boilers are high-tech and safe devices. Like all equipment, they have an expiration date. When conducting timely preventive maintenance, the boiler will last a long time. If the boiler begins to junk or malfunction, it is necessary to immediately inspect it and diagnose it, to identify the cause of the malfunction.

There are a number of common boiler malfunctions. Sometimes the unit refuses to turn on or its operation deteriorates due to a too dirty coarse filter. Also, users are faced with the problem of pollution of the heat exchanger and chimney. When carrying out repairs, safety precautions must always be observed.

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