What should be the operating pressure in the heating system of a private house?

It is essential to comprehend the operating pressure in your home’s heating system to guarantee effective and efficient heating throughout. The force at which water flows through the system to heat radiators or underfloor pipes is referred to as operating pressure. For the system to operate as best it can, this pressure must be kept within a certain range.

For the majority of residential heating systems, 12 to 25 pounds per square inch (psi) is the recommended operating pressure. This range is made to provide effective heat distribution while avoiding overstressing the system’s parts. Inadequate heat distribution can be caused by too low pressure, and leaks, component damage, or even system failure can be caused by too high pressure.

It is crucial to keep the operating pressure at the proper level for a number of reasons. First of all, it guarantees that heat is dispersed uniformly throughout your house, avoiding cold spots and guaranteeing comfort in the winter. Second, adequate pressure lessens the wear and tear that poor water circulation causes to the components of your heating system.

The majority of heating systems have a pressure gauge installed in order to track and modify the operating pressure. With the help of this gauge, homeowners or HVAC specialists can quickly check the current pressure and make any necessary adjustments. Frequent pressure checks can help avoid potential problems and guarantee your system runs well all year round, especially before and during the heating season.

Types of heating systems

There are two main categories of heating systems: open systems, which are in direct contact with the environment, and closed systems, which operate under higher pressure.

Maintaining the proper operating pressure in your private home’s heating system is essential for trouble-free operation and effective performance. The operating pressure makes sure that heat moves through your underfloor pipes or radiators in an efficient manner. While excessively high pressure can strain your system and result in leaks, too low pressure can cause weak heating or even damage to your boiler. Maintaining the proper pressure level, usually between 1 and 1.5 bar (15 and 22 psi), will keep your heating system operating efficiently and save you money on repairs. Knowing and keeping an eye on this pressure will guarantee that, during the winter, your house remains toasty warm without wasting energy or wearing out equipment.

Open

An open expansion tank (tank) is a necessary component of an open heating system. The installation location of the system is determined by looking at its highest section. This tank serves as a safety valve, an air vent, and an expansion tank (which compensates for the excess coolant that expands during heating). It is necessary to install the expansion tank at a stable slope in order to guarantee air removal through it.

The hydrostatic pressure of the water column is indicated by the operating pressure indicator in the heating system on each circuit segment. The coolant level in the expansion tank is at the top, and the column limits the measurement point at the bottom. 0.1 kgf/cm2 is the overpressure parameter for a one-meter water column. The pressure drop needs to equal one atmosphere for the water column to rise by 10 meters.

Closed

The following is used to control the pressure inside a closed heating system with a fixed volume:

  • Water pumping. To achieve this, the heating circuit is connected to the cold water supply system using a jumper. Using a tap, you can solve the problem of how to create pressure in the heating system of a private house, as well as fill the circuit that was emptied before carrying out repairs.
  • Membrane expansion tank. A membrane tank is a steel container consisting of two halves. An elastic rubber membrane is used for separation. The operating state is characterized by the presence of air with excess pressure in one of the halves (it is also called charging pressure). The other half of the tank contains coolant. The purpose of the tank is the same as in an open system: compensating for the water pressure in the heating boiler when it is heated. Air differs from liquid in that it is easy to compress, which is why the rate of pressure increase in the circuit is an order of magnitude lower.

In addition to its primary purpose, the tank can also be used to mitigate pressure drops within the closed circuit. This is a reference to water hammers, which are caused by an abrupt halt in flow. Regarding the operating pressure indicators, they read 1.5 kgf/cm2, which is the factory tank charging pressure as stated in the instructions when the boiler is turned off. There is a maximum allowable value of 2.5 kgf/cm2. Normally, the safety valve opens when the pressure reaches 2.5 atm.

Central heating

It is not always the case in the private sector to use autonomous heating. For instance, in regions with severe weather, homes receive heat through the main heating system’s taps. The autonomous water-jet elevator at the front of the house controls heat transfer by recirculating a portion of the coolant.

In these situations, the working pressure is comparable to that of apartment buildings in the following ways:

  • On the supply pipe: 5-7 kgf/cm2.
  • On the return pipe: 3-4 kgf/cm2.
  • After passing the elevator: 0.1-0.2 kgf/cm2 more than in the return.

Restrictions

The stated operating pressure in the heating boiler for all contemporary pipes and heating radiators is 6 atm. There are several explanations for why the autonomous heating parameters are not increased to at least 5 bar.

Causes of the heating system’s pressure effects include:

  1. If you increase the pressure in the circuit, it will not bring any dividends. The height of the water column is used only when filling an empty system. A simple calculation shows that if the excess pressure is 1.5 atm., this will cause the water to rise by 15 m. Considering the legal restrictions on the height of private buildings (three floors), this is more than enough.
  2. Unforeseen situations (water hammer or pressure surges due to a broken safety valve). The safety margin of batteries and pipes in such situations allows you to avoid serious accidents.
  3. You need to understand that the strength and service life of pipes indicated by the manufacturer does not always correspond to reality. First of all, we mean plastic products popular in private construction. In elevated temperature mode, a decrease in the declared characteristics is observed.

PN25 polypropylene pipes can only reliably verify their stated 25 atm and 50-year service life at room temperature. A closed heating system’s operating pressure will rise to 7-9 atm if the temperature is raised to 90 degrees, which could destroy pipelines. Although this doesn’t always result in significant leaks, it is still important to consider this.

Increase in pressure

The following could be the cause of a sudden rise in pressure in the heating circuit that triggers the safety valve:

Damage to the jumper’s valve that controls the system that supplies cold water. One issue unites plug valves and screw valves: when closed tightly, neither type can offer perfect tightness. The most common causes of gaps are scale buildup between the screw valve and the seat or wear on the gaskets. Additionally, this may scratch the plug and faucet body. Water slowly seeps into the circuit in closed heating systems when the system’s pressure rises above that of a cold one, which occurs frequently. A safety valve is then used to release it into the drainage system.

The volume of the expansion tank is insufficient. There is not enough room in the tank to fully compensate for the coolant’s heating and subsequent volume increase. An instantaneous rise in pressure upon lighting a fire or turning on the boiler is indicative of this issue.

It is preferable to swap out the old valve for a contemporary ball valve in order to solve the initial malfunction. Stable tightness in the closed position and an extended service life are the distinguishing features of this kind of shut-off valve. Additionally, this does not require regular maintenance. After several hundred closing cycles, the gland nut under the handle needs to be tightened.

You will need to replace the expansion tank with a larger tank in order to address the second issue. Installing an extra expansion tank in the circuit is an additional option. For the system to function flawlessly, the expansion tank’s volume ought to be roughly one-tenth of the total coolant volume.

An increase in pressure can occasionally cause a circulation pump to activate. If the pipeline has high hydraulic resistance, this is typical for the filling area after the impeller. Usually, the cause is an inadequate diameter. In such a case, there’s no need to freak out because the issue can be resolved with a straightforward security group installation (at a sufficient distance from the pump). It is only appropriate to replace the filling with a larger diameter pipe if there is a significant temperature differential in the coolant circulation direction between the boiler’s first and last radiators.

It is essential for the longevity and efficiency of your home heating system to know the ideal operating pressure. When the system is cold, the recommended pressure usually falls between 1 and 1.5 bar. This guarantees the efficient and strain-free operation of your boiler and radiators.

Sustaining the proper pressure helps avert problems such as insufficient heat distribution or possible component damage. Excessively high pressure can cause leaks or damage to the boiler, while too low pressure can cause cold spots or even the system to shut down completely.

It is crucial to check and adjust the pressure on a regular basis in accordance with manufacturer guidelines. Your heating system’s lifespan can be greatly increased by performing this easy maintenance task, which also lowers the need for expensive repairs.

In particular during the winter months, you can guarantee comfort and dependability throughout your house by being aware of and in control of your heating system’s operating pressure. This minor yet crucial element of house upkeep yields significant benefits in terms of effectiveness, coziness, and tranquility.

Video on the topic

Features of a closed heating system

🔺️Pressure in the heating system of a house / pressure in the heating system of a private house / what is the pressure ?🔻

What water pressure should be in the water supply system of a private house??

Heating. Blood pressure dropped. We fix it ourselves

heating system pressure

What pressure should be in the expansion tank!

Heating pressure surges and drops. Expansion tank.

How to set up an expansion tank in a heating system

What factor is most important for you when choosing materials for building a house??
Share to friends
Milan Yashina

Design engineer, specialist in development of design documentation. I will help you correctly design your home or other building.

Rate author
StroyArsenal62.com
Add a comment