Heating leak sealant

Heating leak sealant Sealant for heating systems to eliminate leaks - properties and types

Even the highest quality heating systems need protection from damage and after a while they begin to require repair work. In order to eliminate the leakage of pipes or batteries, you can use a sealant to eliminate the leak - a special repair tool that allows you to reliably and quickly restore the operation of the heating system.

The process of sealing a heating system is usually understood as the elimination of hidden and open leaks that appear in any areas.

In fact, such a problem belongs to the category of emergency situations and requires an urgent solution, and also strictly adherence to technology during the work.


What is sealing required for

In addition to sealing hot or cold water leaks, sealing may be required in such cases:

  • For laying water pipes.

  • When installing threaded connections.
  • For sealing the boiler roof.
  • For installing a warm floor system.
  • For strengthening the radiator connections after disassembling into sections.

Heating System Sealant is a self-sealing multi-purpose solution that helps seal leaks in pipes and bonding points.

Most sealants are suitable for both indoor and outdoor use and can be poured into the expansion tank and other areas of the water system.

Please note that the use of a sealant allows you to quickly restore the functioning of the heating system, and at the same time without destroying the integrity of the floor and walls. especially often, sealants are used when domestic pipes are in places inaccessible for open operations, and even if it is not possible to eliminate the leakage of solders by applying a clamp.

Basic requirements for compositions

Sealant can be used for polypropylene, bimetallic and other heating pipes. but before buying, it is important to clarify that its characteristics correspond to one or another pipe material, because plastic compounds are not suitable for metal networks.

You can get acquainted with such information on the packaging, which always contains all the exact data about the properties and composition.

Moreover, the sealant must meet the following requirements:

  1. Resistance to adverse factors. The water in the pipes will be under pressure and still hot. For this reason, the product must necessarily be resistant to moisture, does not react to temperature extremes, and also to the effects of aggressive chemical environments. Its agent is used in steam systems, it must be high-temperature (heat-resistant).

  2. Long operational life. The operating time of the entire heating system will depend on this factor.If the composition is reliable, the system will function for at least 7 years. The price of such funds is usually quite high.
  3. Elasticity.

    Leakage sealants after curing must retain their plasticity. So they will simply and without destruction and detachment transfer the contraction and expansion of the base material, which inevitably appears during temperature extremes.

What types of products are there?

Types of sealants

The selection of a hermetic agent is not simply due to the material pipes, but also by the type of heat carrier used, and also by the presence of a heat exchanger. If you choose an unsuitable medium, you can get blockage of pipes in any place of the heating system. Consider a sealant for repairing radiator leaks.

Various substances can be used as a warm carrier, and the sealant should in no case react or collapse from contact with them, and on this basis, the means can be divided into those that contact methods:

  • Heating leak sealant With antifreeze.
  • With water (simple, softened with complexones or magnetized).
  • With oils.
  • With steam or gas.

A separate line will be a sealant for cool water pipes, which is still applied to the valve thread, and is used to seal joints.

In terms of consistency, sealants are fluid and pasty. Another pipe sealant can be classified according to the following properties:

  1. Drying compounds. As they dry, they become perfectly dry, and if the application and drying technology has been violated, the products are able to shrink and crack quickly.
  2. Non-drying compounds. Ideal for removing small leaks, sealing threads, although they can squeeze out at joints under pressure.

Please note that among the most popular brands of sealants we single out "Aquastop 2100", "Blok Seal 100" and BCG. By their composition, the funds can be divided into several groups, which are described below.

Detailed view of species

Based on oligomers

Depending on the functional group used in production such funds can be divided into polysiloxane and polysulfide. Sealants made from polysulfide oligomers are much more common for heating systems. They have a unique set of properties - oil resistance, gasoline resistance, gas tightness, resistance to the atmosphere, and also the ability to operate for a long time in various temperature ranges.


Most of the acrylic type products are not suitable for repairing the heating system in an apartment or a private house. Only certain brands can withstand temperature changes and are able to boast of thermal stability.For example, anaerobic sealants are suitable for sealing pipes, as well as radiators - a type of acrylic compound that, when it enters an airless type environment, fill a closed volume (chip and crack) and form a homogeneous polymer-type mass. Such compounds are able to withstand high temperatures, and they are also elastic and durable. Joints and seams are subsequently allowed to be cleaned with alkaline and acidic substances, because the sealants are highly resistant to chemicals.

And yet they have one drawback - structural dismantling will be very difficult, because it will become monolithic.


Such materials can be used at temperatures from -20 degrees to +40 degrees, that is, to the number of thermally stable not belong. For this reason, they are used only in construction to seal interpanel joints, plumbing equipment and glass units, and are not used to repair the heating system.


Silicone-type leak-proof heating sealant is the most versatile and popular. Most of these funds are high-temperature, and therefore suitable for work in the heating system.

They can be pasty and liquid, while the former have thixotropic properties (do not flow after application). Technical characteristics of silicone-type compounds are as follows:

  • Possibility of operation from -65 to +300 degrees.
  • Adhesion to any surface.
  • Penetration even into very small depressions and cracks.
  • Curing at room temperature.

  • Resistance to moisture and aggressive chemical compounds.
  • Elasticity.
  • Eco-friendly safety.
  • Durability.
  • Durability.

When buying a silicone type sealant, you should pay attention to the specific variety. Means can be acidic and neutral, and the first ways to corrode metal, therefore, are not suitable for metal pipes.


Means based on polyurethane are made one-component and two-component. The former are inexpensive, but dry out much longer. The latter, after reacting with the hardener, quickly polymerize, and as a result, an elastic and strong connection is created.

Such compositions are suitable for all types of materials, including metals, and they also do not provoke corrosion, on the contrary, they protect the elements from damage. The sealants are durable, resistant to aggressive chemicals, mechanical stress and are characterized by low consumption.

Liquid sealant for the heating system

Liquid sealant should be used where there are hidden leaks, and there is still no access to the place of formation defects. The material should be poured into damaged tubes along with the heat carrier.In the area of ​​the crack, the sealant will definitely come into contact with air and will begin to polymerize, sealing the flaw.

Among the liquid type options there are those that can work in water, antifreeze, and are suitable for plastic or metal pipes.

Technology and methods of using the agent for heating systems

First, you should choose a suitable agent and accurately calculate its amount, which will directly depend on the volume of the heat carrier. Usually for 70 liters of fluid, 1 liter of sealant should be taken.

External type of processing

For external affairs, work can be attributed to sealing joints and thread connections. They must be performed in the following order:

  • Heating leak sealant Drain all liquid from the heating system.

  • Find the damaged area.
  • Clean the flawed area of ​​dirt, dust and old sealant.
  • Degrease.
  • Application of new sealant.
  • Wait until dry.

  • Pour thermal media into the system.

Consider another processing method.

Internal treatment type

If you need to fill sealant to eliminate radiator leakage inside the system, you need to buy a liquid agent. Water from the heating system should be drained into containers, and the sealant should be diluted with water. The "Mayevsky" valve should be unscrewed from the radiator, and a pump should be connected in its place.

Fill the systems with a liquid with a sealant, and the pressure should be increased to 1.5 atm. After 7 hours, the sealant will completely harden. Next, the thermal carrier should be drained again, and a new one should be introduced instead, but without sealant. So repeat a couple more operations, which is necessary to remove the remnants of uncured sealant in the pipes.

Check for cracks and defects after 72 hours and repeat the process if necessary. If the water leak is more than 30 liters per day, there is no flush to seal it - only a major overhaul with a complete replacement of a piece of pipes is required.

Preparation work before applying the sealant

In order to prepare the system, unscrew all the valves and remove the filters. This is required to drain water and air (antifreeze). To find a leak, the pipes must not be wet - for this, install a pump on the first radiator, which will remove excess air and heat the inner surface of the pipeline to +55 degrees.


The rate of addition of the compound for sealing may vary depending on the brand and type. The concentration of the agent should be calculated as accurately as possible, otherwise the effectiveness will tend to zero. To do this, carefully read the instructions and determine the volume of the thermal carrier.

You can make the calculation like this:

  • Direct measurement - take containers of the required size, pour water from the pipes into them and find out the total volume of liquid.
  • Indirect measurement - count the entire length of the pipes, multiply by the cross-sectional area, add to the indicator of the volume of the radiators and the boiler (you can see them in the passport for the products).

After that, you should determine the rate of sealant according to the instructions for a particular tool. Usually it is not more than 1 liter per 80 liters of heat carrier. Two-component products must be mixed immediately before use, and the two substances must be combined according to the ratio indicated in the instructions.

Setting the heating system for pouring

To prevent the agent from freezing in the pipes ahead of time, but having reached the point of leakage, remove air from the heating system. After removing the filters and unscrewing the taps, the automatic pump should be turned on for a couple of hours and this is enough to flush out the remaining gas.

How to pour sealant

In a huge container, a solution of sealant and water is prepared, it mixes well. The liquid is immediately introduced into the heating system by means of a pump - high speed of operation helps to reduce the risk of contact with air. After that, the heating system starts up in normal mode with water at a temperature of +50 degrees. Control measures are carried out after 4 days and they will help to check whether the sealing was carried out efficiently. It is also desirable to carry out a pressure test - starting the heating system under pressure, and for this it is worth calling an experienced master.