Operating principle of a gas heating boiler

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Published: 10/13/2020

Reading time: 3 min



The electronic board is what connects all the electronic components in the heating boiler, helping it to operate efficiently. For example, when ignited, it sends a signal to start the fan and centrifugal circulation pump.

Then the controller receives a signal from the primary air pressure sensor and compares it with the norm, only after this a command will be given to the shut-off valve to supply gas to the main burner. If a failure occurs in the boiler and the diagnostic system displays an error with the code “board”, it will need to be replaced or repaired.

Repair of gas boiler circuit boards can only be carried out by service organizations that are ready to provide a guarantee for their work for at least 6 months.

  • 1 Why the control board fails
  • 2 Signs of a broken gas boiler board
  • 3 Repairing the electronic boiler control board yourself
  • 4 Repair of electronic boards by specialists
  • 5 Where to order a board with delivery

Why does the control board fail?

The board operates under very extreme conditions; it is forced to constantly monitor the operation of all sensors and actuators of the boiler. This ensures that the unit will operate within acceptable values ​​for performance, temperature and pressure of the environment.

As soon as it notices any abnormalities, such as fluctuations in air pressure due to a blocked chimney or a faulty fan where adjustment is not possible, it blocks the gas supply to the burner and displays a fault code.

The error code helps the boiler repair service company quickly eliminate the problem. This makes repairs faster than troubleshooting from scratch and helps reduce boiler repair costs.

The boiler lock itself is considered a safety measure to prevent damage to expensive components, such as the boiler heat exchanger.

Reasons for failure of the boiler board:

  1. A leaking boiler, pump or cracked heat exchanger increases the humidity inside the structure and the condensation process on the board elements.
  2. Cracks and fractures on the printed circuit board.
  3. Weak or damaged solder joints.
  4. Degradation of the constituent elements of the circuit: a dried-out capacitor with an increased ESR in a switching power supply.
  5. Errors with EEPROM memory.
  6. Voltage surges in the electrical network when a voltage stabilizer or uninterruptible voltage source is not connected in front of the unit. In this case, any technical failure at the substation from poor-quality grounding, burning “0” or a lightning discharge can damage the board.
  7. A manufacturing defect, after which it will be impossible to regulate the operation of the boiler.
  8. Unprofessional repair.
  9. Boiler vibration, board components are extremely fragile. Excessive vibration can cause the unit chip and connections to the printed circuit board to break and damage the wiring. Before repairing it, you need to eliminate the vibration. The most obvious components to check are both the pump and fan.
  10. Technical wear and tear, after 14 years of operation.


Persons who have examined this passport are allowed to service the device.

Installation and operation of the devices must comply with the requirements of the “Rules for the design and safety of operation of hot water boilers, water heaters and steam boilers with excess pressure”, as well as the requirements of the “Safety Rules for Gas Distribution and Gas Consumption Systems. PB 12 - 529", approved by the State Mining and Technical Supervision of Russia.

The operation of the devices must be carried out in accordance with the “Fire Safety Rules for residential buildings, hotels, dormitories, administrative buildings and individual garages PPB - 01 - 03”.

Operation of the device is only permitted with properly functioning automatic safety and thermal control.

Gas safety automatics must provide:

  1. Reducing the gas supply when the water temperature in the heating system reaches the set value.
  2. Shutting off the gas supply to the main burner when the set heating temperature is exceeded.
  3. Turning off the gas supply to the device in the following cases:
      when the gas supply to the device is stopped (within no more than 60 seconds);
  4. in the absence of draft vacuum or in the boiler furnace (for a period of no less than 10 seconds and no more than 60 seconds);
  5. when the pilot burner flame goes out (within no more than 60 seconds).

When operating the device, the hot water temperature should not exceed 95 °C.


  1. operate the device with the heating system partially filled with water;
  2. use other liquids instead of water as a coolant**;
  3. install shut-off and control valves on the supply line and pipeline connecting the heating system to the expansion tank;
  4. operate the device if there is a gas leak through the gas pipeline connections;
  5. use an open flame to detect gas leaks;
  6. operate the device if there is a malfunction of the gas network, chimney or automation;
  7. independently eliminate malfunctions in the operation of the device;
  8. make any design changes to the apparatus, gas pipeline and heating system.

When the device is not working, all gas valves: in front of the burner and on the gas pipeline in front of the device, must be in the closed position (the valve handle is perpendicular to the gas pipeline).

Any malfunctions when operating the device on gas must be immediately reported to the emergency service of the gas operating company.

If gas is detected in the premises, you should immediately stop supplying it, ventilate all premises and call emergency or repair services. Until the malfunction is eliminated, it is prohibited to light matches, smoke, or use

** It is allowed to use household coolant “Olga” (manufacturer: ZAO Organic Products Plant) according to the instructions for use. After a period of operation, the coolant must be drained and disposed of.

The manufacturer reserves the right to make changes to the design and appearance of the product. This technical documentation may differ from the description above; see the operating manual enclosed with each boiler upon purchase.

Signs of a broken gas boiler board

The first sign that the unit's electronic board is not working is that the display panel works intermittently. This causes the LED lights to turn on and off and sometimes cause control panel functions to not work properly.

The most likely cause of this problem is damage to the wiring connecting the PCB to the user interface. A service engineer can gain access to the rear of the display panel to visually inspect wiring and connections.

If there are obvious signs of loose or damaged connections they will need to repair or re-fasten them.

The most common signs of electronic board malfunctions:

  1. The boiler shuts down before the operating temperature of the coolant is reached, it constantly turns on/off, which puts excessive pressure on the boiler components. A technician should check the condition of the wiring and connections to the NTC thermistors.
  2. The fan does not start or constantly operates with overheating of the wire, while the technical condition of the circuit components is satisfactory.
  3. The gas valve does not open during ignition, with normal parameters in the gas network and its performance. The service engineer should first check the communication line between the gas valve and the board. A possible failure could also be related to the fan. Once the board recognizes that the fan is running and therefore removing harmful gases from the boiler, it will command the gas valve to open, thereby ensuring a stable gas supply to the burner.
  4. The PCB (Power Control Block) indicates a memory error by displaying the corresponding fault code on the display panel. This is a memory failure and is due to an incorrect PCB configuration. Such errors occur when a new board is installed in which the boiler code for communication has not been entered.
  5. PCB is not responding. Although there are dozens of different boilers using the same type of PCB, it may happen that the new board will not work without the correct boiler chip card. The chip card itself may also be faulty. The service engineer must remove the boiler body to get to it and check that it is inserted correctly. These are fragile parts, so the slightest vibration of the boiler could dislodge it from the workplace. Then they check it and put it in its place.
  6. If the boiler starts smoking and fault codes appear on the display, then most likely the board has been damaged by water and requires repair or complete replacement.
  7. No power to PCB or display panel, requires complete PCB replacement.

Explosion diagram for the Alfa-Kalor AOGV-32-ZP boiler, model 2013

Boiler body Alfa-Kalor AOGV 32 ZP 2013 Hydraulic part of the boiler Alfa-Kalor AOGV 32 ZP 2013 Circulation pump and secondary heat exchanger of the boiler Alfa-Kalor AOGV 32 ZP 2013 Front part of the boiler Alfa-Kalor AOGV 32 ZP 2013

Spare parts for the boiler body Alfa-Kalor AOGV 32 ZP 2013 gv
Spare parts for the boiler body Alfa-Kalor AOGV 32 ZP 2013 gv

Hydraulic and burner part of the Alfa-Kalor AOGV 32 ZP 2013 boiler
Hydraulic and burner part of the Alfa-Kalor AOGV 32 ZP 2013 boiler

Circulation pump and other elements of the Alfa-Kalor AOGV 32 ZP 2013 boiler
Circulation pump and other elements of the Alfa-Kalor AOGV 32 ZP 2013 boiler

Control board and front part of the boiler Alfa-Kalor AOGV 32 ZP 2013 gv
Control board and front part of the boiler Alfa-Kalor AOGV 32 ZP 2013 gv

Repairing the electronic boiler control board yourself

Almost no one carries out such repairs on their own, and not because it is, in principle, impossible, but rather because it is not economically feasible.

Any repaired electronic board must be tested on equipment that is many times more expensive than the board itself. Therefore, no one will buy such equipment for one-time work.

In addition, for the operation of the boiler and its further maintenance under the contract, an official guarantee and conclusion for such repairs will be required, which can only be provided by service centers, since they were previously certified by the boiler manufacturer for the possibility of high-quality performance of this type of work.

DIY gas boiler repair: is it worth it?

A modern gas boiler is a complex system; the main danger in the event of a malfunction is the use of explosive fuel or gas. To control the operation of a double-circuit or single-circuit heating unit, automation is included in the boiler system to maintain optimal operation. Therefore, repair and maintenance of gas boilers is carried out only by specialists, although some components of the system can be replaced independently.

If there is a smell of gas or smoke in the room, you can only completely turn off the boiler yourself, ventilate it and leave the room, going to the next room. Repair of baxi or other gas boilers must be carried out by a specialist, who must be called immediately.

If the combustion sensor or supply gas pipe breaks down, you need to turn off the device, let the boiler cool, and turn off all gas valves. Then you definitely need to check the room for the smell of gas! If there is draft, you can start the boiler again. If there is no draft, turn everything off and wait for the technician: repair of Navien or Vaillant gas boilers is mandatory.

Important! If the boiler overheats, which is a very common occurrence, then repairing AOGV gas boilers will include cleaning the heat exchanger or correcting the operation of the automation. When an overheating sensor is triggered, immediately turn off the boiler and call a professional.

Do-it-yourself repair of a gas boiler can only be carried out if there is visible and easily repairable damage, as well as if the gas supply pipe is dirty. It can be washed with water, cleaned with a cotton swab and dried.

Repair of electronic boards by specialists

When choosing a service organization to repair circuit boards, you need to make sure that it is certified to perform work specifically for a specific boiler model.

Next, you will need to find out the company’s operating forms, it is better if there is an opportunity to work from home. Then, before changing the board, the company will carefully analyze the operation of the unit and the possibility of failures of auxiliary equipment.

Working from home, a service specialist must have a gas analyzer, a diaphanometer and a set of research and repair equipment. Carrying out diagnostics of the operation of the pump, fan and power supply circuits, based on the results of the examination, he identifies a failure.

The specialist’s repair kit should contain a backup boiler board for this model, which he replaces while repairing the faulty one. Such repairs last no more than 2 hours, which is especially important in the cold season, so as not to cool the premises.

In the workshop, a complete diagnosis of the board is carried out on a specialized stand, which simulates the operating modes of a specific boiler unit and records failures with special software.

In addition, a thermal imager, oscilloscope and logic analyzer are used. This repair technology allows you to identify “floating” defects, identify minor defects, software failures, and power surges.

Long-term testing makes it possible to notice and record absolutely all the details of the functioning of the electronics. 70% of board breakdowns in a good workshop are repaired within the first 24 hours; if spare parts are needed, delivery time will take 2-3 days; if components are needed from abroad, repairs can last up to 2 weeks. As practice shows, 90% of boards can be restored.

Pricing principle:

  1. Primary diagnostics are carried out - up to 500 rubles.
  2. Based on the results, the full cost of repair work is determined. The average price for units up to 16 kW is from 3,000 rubles, more than 20 kW - from 4,000 rubles.
  3. Installation of Ariston boiler board - from 1,500 rubles.
  4. Payment is made upon completion of the repair, upon confirmation of the functionality of the board.
  5. Additional costs for transport services within the Moscow Ring Road - 1000 rubles, additional payment for 1 km from the Moscow Ring Road - 30 rubles.
  6. A 6 month warranty is provided.

Despite the fact that the service center gives a guarantee for six months, in fact, a repaired boiler control board can last much longer.

Since 2014, most manufacturers of Western-made heating boilers, especially if they are assembled in other countries, have used inexpensive parts in boards.

Service centers are certified by factories and brand owners who require the use of original spare parts, so quite often after repair the board is superior in quality to the original one.

Explosion diagram for the Alfa-Kalor AOGV-50-ZP boiler, model 2010

Boiler body Alfa-Kalor AOGV 50 ZP 2010 Body, fasteners and thermal insulation of the boiler Alfa-Kalor AOGV 50 ZP 2010 Hydraulic part of the boiler Alfa-Kalor AOGV 50 ZP 2010 Electrical part of the boiler Alfa-Kalor AOGV 50 ZP 2010 Heat exchanger disassembled of the Alfa-Kalor AOGV boiler 50 ZP 2010

Spare parts for the boiler body Alfa-Kalor AOGV 50 ZP 2010 gv
Spare parts for the boiler body Alfa-Kalor AOGV 50 ZP 2010 gv

Elements of the body and fastenings of the boiler Alfa-Kalor AOGV 50 ZP 2010 gv
Elements of the body and fastenings of the boiler Alfa-Kalor AOGV 50 ZP 2010 gv

Heat exchanger, circulation pump, boiler fan AOGV 50 ZP 2010
Heat exchanger, circulation pump, boiler fan AOGV 50 ZP 2010

Electrical diagram of the boiler Alfa-Kalor AOGV 50 ZP 2010 gv
Electrical diagram of the boiler Alfa-Kalor AOGV 50 ZP 2010 gv

Heat exchanger and its elements of the boiler AOGV 50 ZP 2010
Heat exchanger and its elements of the boiler AOGV 50 ZP 2010

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