Error codes for the Master Gas boiler: interpretation of symbols and troubleshooting guides

South Korean gas boilers of the Master Gas Seoul brand are structurally complex functional devices with rich technical equipment. Compact units are literally crammed with devices that ensure stable operation of the equipment and automate the process. All system components are important and interconnected, but any one of them can fail.

Master Gas boiler error codes will help you find out about the occurrence and cause of the malfunction. The alphanumeric combinations that appear on the display will tell you where the violation occurred and will allow you to quickly decide what should be done to eliminate it. It is extremely important not to waste time when restoring the unit’s functionality. Do you agree?

We will tell you how boiler malfunctions are coded by the manufacturer. We will tell you what actions need to be taken to correct the situation. From the article we presented, you will learn what repairs are needed to restore the unit and which of the shortcomings in the work can be eliminated with your own hands.

Briefly about the device and functional systems

The company “Daesung Celtic Enersys Co., founded in the Republic of Kazakhstan” Ltd.” offers Russian consumers a line of wall-mounted gas boilers serving facilities ranging from 110 to 210 m². Double-circuit units from South Korea with the Master Gas Seoul logo and the following letter designation from 11 to 21 are adapted to domestic operating conditions.

In essence, they are a thoroughly thought-out and carefully equipped mini-boiler room. It has its own protection systems, stimulation of the movement of the heated medium, removal of air pockets and combustion products and other devices.

Despite the high quality of assembly, as well as the scrupulous selection of components and parts, from time to time one of them becomes unusable. Irregularities in operation occur due to simple wear and tear, end of working life, etc. Unfortunately, the list of common reasons also includes the incorrect attitude of owners towards complex technical equipment.

In addition, the units process gas to produce heat. And this type of fuel is extremely toxic, so breakdowns should be taken seriously. Any violation may lead to undesirable, threatening consequences, which are best prevented at the initial stages.

Before you begin deciphering codes that indicate malfunctions, you should carefully familiarize yourself with the design features, structure and components of the gas boiler

The important components responsible for the operation of the wall-mounted boiler model include:

• Burner block. Located in the combustion chamber. Consists of a burner and a manifold with gas supply nozzles. Responsible for preparing the gas-air mixture, or more precisely, for mixing blue fuel with air in the proportions required for normal combustion.
• Spark plug. Located to the left of the burner. When activated, it produces a spark that ignites the gas-air mixture.
• Circulation pump. It stimulates the movement of the coolant along the circuits located inside the boiler and, after heating, “pushes” it towards the exit into the heating system and the hot water supply pipe.
• Expansion tank. Accepts the volume of coolant formed when water is heated.This eliminates excess pressure, which could lead to depressurization of the circuits.
• Air vent. A device for automatically relieving air pockets from closed pipeline systems helps create a stable pressure without excesses or drops in pressure.
• Temperature and DHW flow sensors. Used to automate the process. The first one fixes the upper and lower heating limits in order to send a command to turn the burner on/off. The second gives a signal to switch to the supply of sanitary water at the moment the tap opens.
• Heating temperature sensor. Reacts to changes in coolant temperature. Automates the heating procedure.
• Gas valve. Regulates the supply of gas to the combustion chamber through the nozzles of the gas manifold. Blocks the fuel supply to the burner in the event of a threatening situation.
• Pressure meter. Controls water pressure, gives commands to turn off the unit when the pressure drops or exceeds.
• Fan. Stimulates the removal of gaseous fuel processing products into the chimney. An air pressure switch is responsible for the operation of the fan itself, which stops the boiler in the absence of draft.
• Ionization candle. Detects the presence of flame when the burner is running. If the fire goes out for any reason, this device will give a command to stop the gas supply.

Each of the listed devices performs its own area of ​​work. In addition to them, there is also an important group that prevents the occurrence of dangerous situations. These include a safety valve, a thermal relay that prevents overheating of the heat exchangers, and other equally important parts and system components.

Deciphering codes and ways to deal with failures

Let us immediately note that serious violations in the operation of the heating gas unit must be eliminated by employees of the organization with which the contract for servicing gas equipment has been concluded.

All actions by amateurs inside the “mini-boiler room” are strictly prohibited. Simply put, if you need to remove the casing from a gas boiler to fix the problem, you shouldn’t “climb” into it yourself.

However, the owners must know what happened to their device in order to decide whether they need to call a technician or the problem can be solved by simply cleaning the device clogged with carbon deposits. Let's look at what errors the manufacturer coded and what to do if the code appears on the electronic display.

Factory coded violations and errors

Error A2. This is a signal about a malfunction of the fan.

There are three reasons for malfunction:

• The device is not receiving power.You need to check the wiring that the fan is equipped with and the connections. It is possible that the contact is simply broken somewhere.
• The fan has failed. It doesn’t matter whether it has served its purpose or broken for some other reason, the fan will have to be replaced. If it “flies” during the warranty period, then the gas workers must supply a new one.
• The fuse has blown. With this device everything is extremely simple. It must be changed immediately.

Regardless of the type of failure, the operation of the boiler will be stopped by the pressure switch. Indeed, due to the inoperability of the fan, caustic, toxic smoke may enter the premises. The owners need to turn off the boiler and call a technician from the service center.

The fan is an important component of a gas heat generator. Its responsibility is to remove products from the processing of blue fuel in order to obtain thermal energy

Error A3. Pump failure warning.

If the pump stops working, the heated coolant will not flow into the heating appliances, and hot sanitary water into the mixers. The standard consequence of error A3 is the Master Gas boiler stopping by the thermal relay. For a blocked unit, you will need to buy a new pump.

The most economical and humane option for a breakdown for owners is a violation in the wiring. If a wire is pinched somewhere or a contact comes loose, the technician will promptly fix it and start up the equipment.

If the pump is working properly and the wiring is not damaged, which can be found out by checking, and the thermal relay turns off the boiler, then the reason is not the pump at all. This means that the thermal relay itself requires replacement.

The circulation pump from Grundfos almost never fails. All his problems are most often associated with electrical circuit violations

Error A4. The boiler is blocked by a tripped thermal relay.

Thermal relay is a protective device that responds to overheating of the heat exchanger. Most often, the temperature in Master Gas boilers is exceeded and error A4 “pops up” on the display occurs due to a breakdown of the pump. If the coolant does not circulate, the boiler continues to heat it. As a result, the water in the heat exchanger boils and the unit is blocked.

Note that overheating occurs not only due to pump failure. It often occurs due to slow movement in pipes “overgrown” with mineral deposits. The owner of an autonomous system can clean the heating himself, but it is better for a specialist to remove “growths” from the heat exchanger.

The thermal relay blocks the unit if overheating of the coolant or sanitary water is detected. If heating is carried out in normal mode, but the relay turns off the boiler, then it will have to be changed

It should be remembered that cleaning is not covered by the list of warranty obligations of the manufacturer of the technical product. They are carried out at the expense of the owners, therefore it is better to prevent the deposition of sediment on the walls of the pipes. To do this, you need to try not to change the coolant in the system without apparent need.

Error A5. Coolant pressure drop.

If error code A5 appears on the electronic display or on the display of the PU boiler of the Master Gas brand, it means that there is a sharp change in the heating circuit pressure decreased.

This violation also has three reasons:

• Airlock. They often appear when the heating system is filled with coolant, less often when water boils and the thermostat does not work. The user can remove air pockets by bleeding through Mayevsky cranes at the batteries. You need to start bleeding to the device furthest from the boiler.
• The heating pressure sensor is broken. If bleeding air from the radiators does not help, you will have to change the coolant pressure sensor.
• The connection between the sensor and the electronic board is broken. To identify the exact cause and location of the connection circuit break, you need to check all contacts and wiring between the control board and the sensor.

In short, if you Bled the air out of the batteries, and this did not help, turn off the boiler and call customer service.

The pressure sensor detects excess of standard values ​​in the system and transmits information to the control board, which turns off the boiler. Timely blocking of operation protects the unit from depressurization of components and increases its working life

Error A6. Ignition does not work.

There are plenty of reasons for this error, most of them are associated with the deposition of combustion products on the spark plug or with electrical wiring problems:

• Burner block clogged. It is necessary to clean the burner and gas nozzles from carbon deposits and soot. For cleaning, the burner with the manifold is removed from the gas chamber and treated with a brush. Carbon deposits from ionization and ignition spark plugs are cleaned off with fine sandpaper. Then they wipe everything with a damp cloth and clean the internal channels with a brush.
• The spark plug is not working. It may either be faulty or the electrical wiring connected to it may be damaged. If the spark plug electrode is simply covered with soot, it needs to be cleaned, the device itself must be wiped and degreased.
• The ionization spark plug is not working. There are two possible solutions: either the catfish “flew” or the wiring came loose somewhere.
• The ignition transformer does not work. The situation is like with spark plugs: they themselves are broken and require replacement, or there is no contact somewhere in the electrical circuit.
• Gas supply has been disrupted.This is the most serious and dangerous cause of error A6. It requires mandatory contact with the gas specialists, unless, of course, you yourself forgot to open the gas valve at the entrance of the gas pipeline to the boiler.

In case of interruptions in the gas supply to the burner, contacting the gas company is mandatory for those whose boilers are fed by main gas.

And owners of autonomous systems need to first check the pressure in gas holder or cylinders. Now, if everything is in order with the gas source, you need to call the technicians from the service company.

The duty of the flame ionization spark plug is to register the combustion process in the combustion chamber. If it detects an extinguishment, the boiler will be immediately stopped and the gas supply will be stopped.

Error A7. Damage to the gas valve.

Gas valve malfunctions are traditionally associated with:

• With a break in the modulator coil. There's nothing you can do about it; you'll have to replace the valve completely.
• With damage to the electrical circuit. You need to check all contacts and wires for poor connections or broken conductors.

For check gas valve To ensure functionality, one of the wires is disconnected from the modulator coil. If, after reconnecting, the flashing A7 on the display does not disappear, get ready to buy a new device and replace it.

The gas valve is needed to adjust the fuel flow characteristics. If it is unsuitable for further use, it is replaced

Error A8. Flame that does not go out after turning off the burner.

If, after stopping the heating process, a small undying flame remains in the combustion chamber, it means that the gas valve has become unusable. Simply put, the diaphragm located inside the valve is damaged.It is not possible to change it. You need to buy a new valve.

Error A9. Antifreeze mode.

The system is designed to operate continuously during cold periods, even if the boiler itself is turned off. When the coolant temperature drops below the limit stated by the manufacturer, it starts the burner so that it maintains a minimum temperature background. When the temperature drops to +5º C, in addition to the burner, the automation will also start the circulation pump.

If the boiler shows A9, you need to configure and start this mode again. Each owner can do this himself, without calling a specialist.

AA error. Triggering of the heating circuit temperature sensor.

If the temperature sensor installed in the heating circuit has triggered and sent a signal to the thermostat to block the boiler, it means that the water in it has heated above +95º C and is about to boil.

The appearance of the AA error on the display of the Master Gas Seoul device is caused by:

• Shut off communication valves. You need to check whether you forgot to open the path for the movement of coolant, make-up and supply of water before turning on the unit.
• Filter clogged. After turning off the boiler, you need to test the heating filter. If it is clogged with mineral sediment, the coolant does not move because of it. Clean and rinse thoroughly under running water.
• Pump failure. It is necessary to replace the device that stimulates the flow of water through a closed system.
• Inoperative three-way valve. The device that distributes flows to the heating and DHW line needs to be replaced.
• Broken flow sensor. The device recording incorrect readings in the sanitary hot water circuit should be replaced.

If the situation is not promptly corrected and the causes are not eliminated, the consequences can be the most disastrous: from a violation of the tightness of pipes to irreparable breakdown of the unit.

In order to avoid the need to constantly remove the heating circuit filter for cleaning, it is necessary not to create conditions for the appearance of sediment in the system. The easiest way is not to merge or fill the contour unless really necessary

Error Ab. Damage to the heating circuit temperature sensor.

If the temperature sensor recording the coolant readings is faulty, you should check the operation of the device itself or the electrical connections that supply it with energy.

They check it in the same way as a gas valve - disconnect one of the contacts when the boiler is turned off. The appearance of this error on the display after starting the boiler indicates that the problem is not in it, but in the wiring. By testing all contacts and wires, damage is found and repaired.

Ac error. Damage to the temperature sensor of the DHW circuit.

The causes and their search are carried out in the same way as all these measures are done with a sensor that records the temperature in the heating circuit. If this error appears when the wire is disconnected, then the sensor itself is intact. Consequently, it did not work due to a break in the electrical circuit.

Temperature sensors record the upper and lower temperature limits of the heated medium (coolant or sanitary water). If the settings specified by the user are reached, the boiler is started or paused

Error Ae. Malfunction of the air pressure switch.

There are three main reasons for failure of the pressure switch:

• Clogged channels. Moreover, you need to check both the chimney and the air supply pipe into the closed combustion chamber.If a coaxial chimney is used, only this is checked. If detected, the air supply and discharge paths of the gas boiler must be immediately cleared.
• Electrical wiring fault. It is possible that one of the contacts is loose or the wire is damaged.
• Breakdown of the pressure switch itself. If, with a pressure drop of 130 Pa, the contacts of the device do not close, it means that the device itself is faulty. We'll have to change it.

However, in addition to the errors listed above, there are also violations in the operation of South Korean boilers, for which codes have not been developed or accepted. Meanwhile, knowing about them is very useful.

Boiler malfunctions without error code

If your Master Gas boiler refuses to turn on, no error code will appear either on the remote control display or on the electronic board. In this case, you need to check whether the equipment is connected to the network and whether the socket or power supply cable is damaged.

If error codes are not displayed on the remote control or on the electronic board, then one of these control devices is faulty. Most often this happens due to water ingress

After making sure that everything is in order with the power supply, but the boiler still does not turn on, proceed to inspect the electronic board. It is possible that water got on it. To dry it, it is better to use a hairdryer, after which you need to leave the device for a couple of days so that all residual moisture completely evaporates.

Also, the prerequisites for a sudden stop of the boiler include a blown fuse. This part wears out quickly. As a rule, it can be easily replaced.

If you notice popping noises in the burner, you need to pay attention to the condition of the gas burner. It usually starts popping when it needs serious cleaning.However, this can also happen due to incorrect adjustment of the gas valve - the minimum pressure will need to be adjusted.

If it is not possible to achieve comfortable conditions at the correct coolant temperature, it is most likely dirty or faulty. temperature sensor. Needs cleaning, if that doesn't help, replace it.

If there is insufficient output of heated sanitary water from a double-circuit gas boiler, it is worth checking the pressure. It's possible that weak pressure in a centralized system from which water is supplied to the boiler. However, the dirt filter on the water supply line may become clogged or the secondary heat exchanger, called a plate heat exchanger, may become clogged.

A service representative must regularly clean the gas burner and manifold. Remove dust with a rag, remove carbon deposits with fine sandpaper, and clear the internal channels of soot.

If, upon entering your house/apartment, you smell an unpleasant gas smell, it means there is a leak. The main thing here is not to lose your head and time. You must immediately open the window and widen the door to create an air flow, then call the emergency signal. Under no circumstances should you turn on the light, strike matches or use a lighter! Any spark will cause an explosion.

Baksi will familiarize you with deciphering the codes of violations in the operation of the boiler. next article, which we advise not only potential buyers, but also all equipment owners to read.

Conclusions and useful video on the topic

The following video will introduce you to the rules for servicing South Korean boilers of the Master Gas Seoul brand:

The rules and specifics of deciphering errors are extremely useful information that allows you to quickly respond to all possible violations in the operation of the boiler.Still, the owner will be the first to face all types of failures. It is up to him to decide on further actions.

Do you want to share your own experience in deciphering Master Gas boiler errors and promptly eliminating the problem? Do you have useful information not listed in the article? Please leave comments in the form below, ask questions and post thematic photos.