Heating System Pressure Management: Guide and Solutions

The article focuses on a common problem in heating systems: the lack of water. This situation can cause significant malfunctions in the system, compromising the comfort and safety of the environment. We will analyze the role of the filling valve, also known as the charging valve, and provide guidelines for monitoring and maintenance.

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The Charging Valve: Function and Importance

The filling valve in the system plays a crucial role in maintaining optimal pressure within the heating system. Generally located under the boiler, this valve is cylindrical in shape and can vary in size depending on the model of the system, often being among the smallest components of the system. Its main function is to allow water to enter the system when the internal pressure falls below an acceptable level.

System Pressure: Monitoring and Maintenance

An essential component in the maintenance of the heating system is the regular checking of the pressure, which should be carried out every 3-4 months. The pressure gauge, located on the boiler and marked with the term “bar” is the tool through which the pressure is monitored. A correct reading of the pressure gauge is fundamental to identify a potential lack of water.

Pressure Control Procedure

• Locate the Pressure Gauge: It is found on the boiler and displays the pressure in bars.
• Read the Pressure: Ensure that the pressure is within the optimal values specified by the system’s manufacturer.
• Adjust the Pressure if Necessary: If the pressure is lower than the recommended level, use the filling valve to add water.
• Close the Filling Valve: Once filling is complete, therefore upon reaching the operating pressure of 1.5 bar, always close the valve

What to Do in Case of Water Shortage

If a lack of water is detected in the system, it is essential to act quickly to avoid damage. The first step is to open the filling valve to increase the pressure. However, if the problem persists, it may indicate a leak or another technical fault, requiring the intervention of a specialized technician.

Questions and Answers

Here are a series of common questions and answers:

What to Do if the System Pressure Exceeds 2 Bar?

If the system pressure exceeds 2 bar, it is important to first consider the context in which this increase occurs. A common phenomenon is overpressure that occurs when the system is filled while the radiators are cold. In this situation, the pressure tends to naturally increase due to the thermal expansion of the water when the radiators heat up.

In a system at regime, i.e., when the system has reached a stable and uniform temperature throughout the system, a pressure slightly above 2 bar can be considered normal and does not require immediate intervention. This is because thermal expansion is a natural physical process and expected in the operation of the system.

How to Manage a System that Does Not Reach the Necessary Pressure to Reset the Water Shortage Error?

When managing a heating system that fails to reach the necessary pressure to reset the water shortage error, it is important to consider several factors. One of these is the pressure of the water supply feeding the system. During the filling phase, the system’s pressure is directly influenced by the water supply pressure. Consequently, if the system is located in a building above the second floor and is not equipped with a pressure booster, it can be particularly sensitive to these variations.

In these cases, it is suggested to attempt filling the system at different times, preferably when the water supply pressure is higher. This can vary based on several factors, such as water usage in the area and the time of day. For example, trying in the early morning or late evening, when there is generally less water consumption in homes, might increase the chances of reaching the desired pressure.

If, despite these attempts, the pressure does not reach the required level, there may be other causes to consider. One possibility is that the filling valve of the system is clogged with limescale, especially in systems with a storage boiler. This can prevent the proper flow of water and thus limit the ability to reach the necessary pressure. Alternatively, another cause could be a filling valve with a stuck non-return mechanism, which would hinder the correct flow of water in the system.

In both cases, the solution may require the intervention of a specialized technician to clean or replace the filling valve or to resolve issues related to the non-return mechanism.

What to Do if the Pressure in a Cold System is Very Low and Increases to 3 Bar When Heated?

When facing a heating system that has very low pressure when cold and increases up to 3 bar when heated, it is very likely that the problem is related to the heating system’s expansion vessel. The expansion vessel’s task is to cushion the increase in pressure caused by the thermal expansion of water within the system. This component is crucial for maintaining the system’s pressure within safe and stable limits.

In normal conditions, the expansion vessel is inflated with air, and this internal air pressure is regulated during the system’s maintenance. If the expansion vessel is not adequately maintained, it can lose its effectiveness in cushioning pressure variations. This can occur in two main situations:

1. Lack of Maintenance of the Expansion Vessel: If the expansion vessel is not checked and adjusted regularly, the air pressure inside it may not be adequate. This can lead to insufficient compensation for the increase in pressure due to the thermal expansion of the water, causing excessive pressure variations in the system.

2. Expansion Vessel Perforated in the Air Cushion: Another possible cause is the presence of a perforation in the air cushion of the expansion vessel. This problem compromises the vessel’s ability to contain the necessary air to cushion pressure variations, resulting in ineffective pressure management within the system.

To resolve this issue, it is advisable to carry out regular maintenance of the system, including checking and possibly replacing the expansion vessel. If malfunction or damage to the vessel is suspected, it is important to contact a specialized technician for an accurate diagnosis and the necessary repairs. Regular checks and proper maintenance of the expansion vessel are essential to ensure the safe and efficient operation of the heating system.

What Steps to Follow if the System’s Pressure Drops Weekly?

If you notice that the pressure of your heating system is dropping weekly, it is important to assess the situation to determine whether it is normal behavior or a sign of a more serious problem. It is normal to observe a certain decrease in pressure during the start-up period of the heating system, especially if it is equipped with aluminum radiators.

Why Does It Happen During the Start-Up Period with Aluminum Radiators?

During the summer months, the aluminum in the radiators reacts with the water in the system. With the start of the winter mode, the air that has formed as a result of this reaction begins to move through the circuit. This air moves until it reaches the boiler, which, being equipped with an air purging component, eliminates it. This process of air elimination causes a decrease in the system’s pressure. Generally, the problem is resolved after about 2-3 filling cycles of the system.

What to Do if the Pressure Continues to Drop?

If, after a few fillings, the pressure continues to decrease, it may indicate the presence of more serious problems, such as:

1. Broken or Deflated Expansion Vessel: If the expansion vessel is not functioning properly, due to a leak or lack of maintenance, it may not be able to maintain the proper pressure in the system.

2. Leaks in Radiators or Boiler: A leak at any point in the system, whether in the radiators or the boiler itself, can cause a constant drop in pressure. It is important to inspect the system to locate any leaks.

In the presence of these problems, it is recommended to turn to a specialized technician for an accurate diagnosis and the necessary repairs.

How Often Should the System’s Pressure Be Adjusted?

The pressure of the heating system should be regularly checked to ensure its optimal operation and to prevent problems. Ideally, this check should be carried out every 4 months, even during the summer period. The reason for this frequency of control is related both to the nature of the system’s materials that can influence the formation of air and to the use of the boiler throughout the year.

Even if the heating system is not in operation during the summer months, the boiler uses the water from the heating circuit as a medium to heat sanitary water. This water, which circulates only inside the boiler, can experience pressure variations even in summer. Maintaining the right pressure is essential to ensure a constant and efficient production of sanitary hot water.

Furthermore, it is particularly important to check the system’s pressure at the first start-up of the winter heating system. After a period of inactivity, there may be pressure variations that need to be adjusted to ensure the proper and safe operation of the system.

In summary, checking the pressure every 4 months, including the summer months, and an additional check at the beginning of the winter heating season, are recommended practices to keep the heating system in good condition and prevent potential malfunctions.