Frequent error codes of the gas boiler – troubleshooting methods

Gas boilers are essential for maintaining a warm and comfortable environment in our homes. These reliable appliances heat water effectively, which is then distributed throughout the house via radiators or underfloor heating systems. However, problems can occasionally arise with gas boilers, just like with any complicated machinery. Error codes on the boiler display are a common source of annoyance for homeowners. These codes may seem confusing at first, but worry not—they frequently point to particular issues that, with the correct knowledge, can be identified and fixed.

It is essential for homeowners to comprehend these error codes since they can offer important information about the condition of your boiler system. Many error codes can be resolved with basic troubleshooting techniques, but some may call for expert assistance. You may save time and money while making sure that your house remains warm and cozy even on the coldest days by becoming familiar with these error codes and their possible fixes.

It is crucial to stress the value of safety when working with gas appliances before going into specific error codes. In the event that you smell gas or believe there is a gas leak, you must act quickly. Get out of the building, don’t use any electrical outlets or devices, and call the emergency services or your gas supplier right away. Gas leaks are dangerous situations that should never be ignored.

Let us now examine a few of the most common error codes that homeowners could see on their gas boiler screens. We’ll dissect each error code and offer helpful troubleshooting advice to help you effectively fix anything from common problems like low water pressure to more complicated malfunctions. With the right knowledge at your disposal, you can confidently take on these challenges and ensure that your boiler and home remain warm all year long.

What is a gas boiler error

There are a number of causes for halting the heating process, and many of them are related to one another. While the gas boiler is being installed, sensors are tested and calibrated at the factory. Periodically, the electronics poll them and cross-reference the data with what’s stored in memory. Nevertheless, the error code with the highest priority or class is shown on the screen because the gas boiler control unit is unable to follow the network of connections.

Alphabetic codes represent errors related to the condition and functionality of gas boilers. Two digits and a letter from the Latin alphabet make up the standard variant of the code. Certain models additionally show text recommendations on the screen, which makes things easier. A table that is placed on the gas boiler’s body can contain the most significant codes.

Errors are classified as blocking or non-blocking based on their current state. In the first instance, the code or suggestion appears on the screen without interfering with the gas boiler’s ability to operate. In the second scenario, restarting the boiler and resetting the message will not allow the gas heating system to operate.

Comprehending and debugging gas boiler error codes is an essential skill when it comes to keeping a comfortable home. This post explores the typical problems that arise with gas boilers and provides clear instructions for locating error codes and using efficient troubleshooting techniques. With the goal of equipping homeowners with the knowledge necessary to guarantee continuous warmth and comfort during the colder seasons, this resource attempts to explain complex error messages and address underlying problems that are causing malfunctions. Equipping oneself with the knowledge offered here can help save time and money while promoting a safer and more effective home heating system, regardless of the complexity of the repair or the simple reset.

Variants of error codes and measures for their elimination

Determining the state of boiler equipment using a code or text message is challenging. Even the service technicians you have to call ask to listen, look, and do this or that in addition to the error code. This facilitates the process of determining whether the anomalous state is the consequence of a malfunctioning piece of equipment or a lesser issue.

What precisely is in charge of the gas boiler’s electronic block is:

• the presence of gas pressure in the valve and issuing a blocking command to start the burner candle;
• general blocking. The code usually indicates problems with the mains voltage, wiring or earthing of the gas boiler;
• water pressure in the heating circuit and secondary heat exchanger;
• critical overheating of the main heat exchanger;
• The most common variant is the lack of draught in the chimney;
• a drop in the speed of the fan-smoke pump;
• presence and stability of the combustion front. Several error codes can correspond to the flame status;
• electronic control and ignition boards are in good working order.

Numerous gas boilers come equipped with integrated sensors that alert users to three possible problems: a rise in carbon monoxide concentration, a decrease in the coolant circulation pump’s performance, or an inaccurate calibration of the air temperature sensor.

Vaillant

The error code for gas boilers manufactured under the Vaillant brand begins with the letter "F" and is followed by a two-digit number. The sensors’ state and suitability for use are indicated by the codes’ smallest values. The operational conditions and serviceability of the gas boiler units are associated with the numerical index errors with larger values.

The main heat exchanger’s outlet’s broken water temperature sensor is the cause of the F0 and F1 error indication. Careless handling of the sensor, broken contacts, or broken terminal wires could be the cause. Replacing the sensor eliminates the error, but not before using a multimeter to test the circuit from the board to the terminal.

The temperature sensors in the storage tank are the source of error codes F2, F3, and F4. If the temperature of the flue gas or fresh air is higher than what is allowed, an indication will show. The upper portion of the gas boiler is overheating, which validates the message.

Vaillant errors related to breakdown of gas boiler units

A malfunction in the gas supply solenoid valve is indicated by code F27. Occasionally, the flame sensor short circuit causes the error to "pop up."

You can use a multimeter and a lit candle to check the thermocouple. It is not possible to confirm with certainty whether gas is present in the furnace while the boiler is operating; instead, you should replace the gas valve or at the very least, make sure the terminals have opening voltage.

When attempts to start the gas boiler are not successful, error F28 occurs. The code typically indicates a blown gas line or a shortage of gas, but it can actually indicate a variety of issues:

• incorrect settings on the gas pressure board;
• failure of the gas valve opening relay;
• gas valve failure.

In order to solve the issue, the relay and the valve must be unplugged and inspected one after the other, first using a multimeter and then putting operating voltage on the terminals.

Incorrect settings can cause the valve to turn on slowly; in this case, the indicator screen will typically show F62. F29 indicates that there is a gas supply issue. The fan on-off relay is not operating correctly, which is connected to the F33 code indication. Examine the relay alone, followed by the fan and the heat sensor that are attached to it.

As long as the water pressure in the heating circuit is normal, code F75 indicates a pump malfunction.

Vaillant electronic errors

The display will display code F63, F64 if the gas boiler issues are related to the electronics. A single sensor may cause the control unit to malfunction. For instance, the F67 code indicates a failure of the key that regulates the thermocouple’s signal reception. Examine the gas burner’s thermocouple for a diagnosis.

If a failed indicator is not correctly replaced, an F70 error may occur. In this instance, a service technician call will be necessary.

Vaillant codes for water and radiator capacity problems

Significance F71–F72 denotes issues with the heating system’s supply and return line sensors. replaceable sensors allow for repair. The F73–F74 errors indicate a malfunction in the sensors that regulate the water pressure in the pipes and heat exchanger. Sometimes the issue is easier to solve: perhaps the measuring circuit just has no contact at all. In this case, the plug and connection cable need to be inspected.

The most concerning messages are those related to errors F20 and F22. The heat exchanger overheat protection sensor may be malfunctioning, but the first code indicates that it has tripped. The second code indicates that the system’s water pressure is dangerously low. A broken sensor, an issue with the heating radiators’ flow capacity, or a stuck pump could be the cause of this.

The main heat exchanger of the gas boiler may be experiencing coolant issues, as indicated by error codes F23 and F24.

In the first scenario, the electronics draws a conclusion based on the temperature differential between the supply and outlet; in the second scenario, it draws a conclusion based on the coolant exceeding its temperature limit. The pump’s operation is most likely the source of the issue.

Protherm

The "Protherm" brand of Slovak gas boilers is known for its high build quality. Although they are uncommon, system operation issues do happen. A two-digit number and the letter "F" are used to code the message.

F0-F5 errors indicate that either the temperature sensors on the boiler, collector, chimney, heat exchanger’s inlet and outlet, or the contacts themselves are broken. They are not common. The F10–F15 codes, which indicate a short circuit or sensor failure, are far more frequent. determined by using a multimeter to check.

F6, F16: A broken or shorted pressostat sensor can be examined by swapping it out for a malfunctioning one.

Important codes:

1. Problems with the heating system, F20, F21 – the gas boiler is blocked due to overheating, the water at the heat exchanger outlet has exceeded the threshold value. F24 – sudden increase of water temperature, up to boiling. F22-F23 – critically low amount of water, the pump may be defective. F76 – gas boiler overheating protection fault.
2. Problems with ensuring safe operation of the gas boiler. F25 – leakage of gas combustion products into the room, F55 – CO sensor is defective, F35 – violations in the smoke exhaust system.
3. Errors in the operation of the boiler gas burner. F26-F29 codes are related to malfunction of the gas valve, candle or thermocouple. F41 messages signal a disturbance in gas quantity control, F60-61 – problems with the gas valve actuator control, F62 – the valve is switched off.
4. Water Problem Information. F71-F75 codes indicate lack of control of water flow due to faulty flow and pressure sensors.

The failure of sensors is linked to about half of the codes indicating issues with the gas boiler’s operation.

Even the most basic sensors are self-checkable. Specific tools are used to diagnose the others. Calling a master is required if a message containing the codes F63–F67 shows up on the screen; these errors are linked to issues with the electronic control unit.

Baxi

Italian heating equipment is known for its thoughtful design and dependability. Poor water quality and the owners’ unsatisfactory service attitude are more likely to be the cause of the majority of errors that appear on the screen.

Codes can be issued in the format "E00" or "00E," and they are composed of the letter "E" and a two-digit number.

It is imperative to prioritize addressing issues pertaining to boiler startup. Code E03 is typically displayed on the screen. This indicates that a lack of draft in the chimney is preventing the electronics from starting up. A malfunctioning pressostat or an ice-clogged flue pipe could be the cause.

You can try to blow out the tube by pressing your finger on the sensor cover if the fan is humming and the wires are in place. Typically, the boiler ignites.

The second frequent mistake, E10, indicates that the heating circuit’s water pressure is low. To verify the authenticity of the message, you can open the kitchen faucet. In the event that the pressure is satisfactory, the sensor is probably malfunctioning.

It could be a blocked gas burner on Baxi. E01 is the error code. Lack of air, particularly in extreme frost (-15–20 °C), or gas valve actuator failure could be the cause. The ignition unit is broken if the spark plug is not producing any spark. The appearance of the E04 code indicates thermocouple burnout or serious contamination.

The heating system’s and the hot water supply’s temperature control issues are indicated by codes E05 and E06. Most frequently, a gap between the sensor and the control board is the cause.

Gurgling noises in the heat exchanger indicate if the boiler has boiled. The error message E25 will show up on the display.

Usually, a jammed circulation pump is the root of the issue. It’s not too bad if there’s air in pipes and radiators because the pump will still pump water. The Maevsky tap on radiators can be used to remove air plugs.

Error E32 indicates that the bithermal heat exchanger’s flow rate has been violated. It’s thought that scale and dirt build up there, so flushing solves the issue. However, wait to flush it until the part has been examined by a specialist. Reagent treatment frequently causes heat exchangers to leak, especially the older ones. One option is to buy a new one or solder it.

Code E96 indicates low voltage (less than 180 V) in the network; a voltage stabilizer or UPS with double sine wave conversion can be installed.

Navien

Made in Korea, the South. The method used in the design of boiler equipment is suitable, with a minimum safety margin and high build quality. In contrast to European models, there are fewer messages and a more succinct information system. This makes troubleshooting the gas boiler easier. Equipment error codes are displayed on the screen as a two-digit number.

Error 16: The boiler overheating scenario is deemed to be the most hazardous. Since the heat exchanger walls are thin, turning on summer mode should be done without interfering with the pump’s ability to operate if code 16 shows up on the screen.

Three additional messages may precede overheating. Errors 05 and 06 indicate an open or short circuit in the heating system’s water temperature sensor circuit. Code 02 indicates that the heat exchanger is not receiving enough water flow.

Additionally, codes 09, 10, and 27 should be noted as they are frequently related to one another. The chimney is the source of the issue if the boiler indicator reads 27 or 10. Typically, condensate that has been frozen melts when heat is applied, flowing through the boiler. The fan, the terminals, and the sensor can all become wet.

With its strong "pulling power," the smoke pump of the "Navien" gas boilers is highly dependable. The air will be drawn to the last by the fan. Yet, there is a higher chance of sensor failure. Consequently, if error code 09 shows up, it indicates that the motor and diagnostics need to be replaced, maybe with the help of a master.

There is a smoke exhaust sensor in certain models, like the Navien Ace 16A, 20A, and 24A, which are intended to operate with a chimney in private residences. Tar deposits from combustion products are probably the cause of overheating if error code 18 is shown.

The operation of Navien gas equipment is generally stable; however, if the boiler is connected to a gas pipe without a filter, errors 12 or 14 may eventually manifest. Usually, an abnormal operation of the control board or a violation of contact on the terminals is the cause of the latter. Then, an additional error code of 15, which indicates an electronic control unit malfunction, will show up.

Unclean gas can occasionally leave deposits on the flame sensor. Coke and metal salts retain heat, which can cause a hot thermocouple to generate a voltage. As a result, the indicator may display a code indicating a false gas fire even though the gas valve is actually closed.

Error 17 indicates that you need to speak with a master because it is directly related to the system settings.

It can be quite annoying to deal with error codes from your gas boiler, but you can solve them more quickly and effectively if you know what to look for in common problems and how to solve them.

Low water pressure is one common error code that many homeowners run into. This may cause your heating system to shut down entirely or heat inefficiently by obstructing the water flow. This problem is often fixable by checking and adjusting the water pressure in your boiler, which will guarantee even heating throughout your house.

An additional frequent error code denotes a pilot light or ignition issue. Your boiler won’t be able to adequately heat your house if it doesn’t ignite. To restore proper functionality in such cases, it might be necessary to inspect the ignition system, clean the pilot light, or replace any faulty components.

Error codes associated with thermostat malfunctions are also frequently encountered. Your boiler may not reach the correct temperature or may cycle on and off irregularly due to a malfunctioning thermostat. It might be necessary to replace or calibrate the thermostat in order to resolve this problem and preserve ideal heating performance.

It’s crucial to keep in mind that while certain error codes can be fixed with basic do-it-yourself troubleshooting, others might call for expert help. Making complicated repairs on your own without the required knowledge could make the issue worse or even put your safety in danger. Do not hesitate to seek assistance from a qualified heating technician if you are unsure of how to proceed or experience ongoing problems.

Gaining knowledge about typical error codes and how to solve them will help you maintain your gas boiler efficiently and guarantee consistent heating for your house, particularly in the winter. Your boiler will last longer if you perform routine maintenance and take quick action to resolve any problems that crop up, keeping your home cozy all year round.

Video on the topic

Hubert gas boiler setting when it boils, shuts off and error comes out