Heating system make-up: pressure monitoring device

An effective modern heating system is not only a functional boiler, high-quality pipes and sound radiators. To ensure the smooth operation of this engineering network, a number of auxiliary elements are also required: sensors, controllers, relays. Among other things, the heating system must be installed - the unit responsible for the recommended pressure and constant volume of the coolant in it.

Why are recharge devices so important?

During the operation of the heating system, it is practically impossible to avoid reducing the volume of coolant - even if the circuit is ideally designed and professionally assembled. Among the main causes of this phenomenon:

1. Critical changes in the operating mode of the equipment, accompanied by the expansion of the liquid and the need to discharge its excess in the form of steam into the atmosphere.
2. Removing air jams. When opening Maevsky cranes, small water leaks are inevitable.
3. Conducting emergency repair or scheduled preventive maintenance; filter cleaning from pollution.

Also, a lack of coolant can be detected even in the absence of an obvious fact of its loss - due to the formation of corrosion on the inner surface of the pipes. At the same time, the pipes become thinner, the internal volume of the system increases: as a result, pressure gradually decreases in it and air jams begin to form.

There can be many reasons for the loss of coolant during operation of the heating system, but there is always one sure way to eliminate them - installation of a make-up unit

The possibility of micro-leaks should never be ruled out. Identifying such defects is rather difficult, but necessary.

With the automatic heating system replenishment installed, the lack of water in the pipeline will always be compensated in a timely manner, and the pressure will not go beyond the optimal values ​​- this is the key to a consistently high efficiency of the equipment and the absence of emergency situations.

You can find out about recommended indicators of pressure in the heating system from our article:https://aquatech.tomathouse.com/en/otoplenie/documents/perepady-davleniya-v-sisteme-otopleniya.html

The principle of operation and types of node management

The main task of the make-up device is to add the missing coolant to the heating system so that the working pressure returns to normal. When the required value of this parameter is reached, the feed stream is interrupted. In the vast majority of cases, the equipment is connected to a cold water supply, but it is also possible to recharge from a storage tank.

In addition to a convenient automatic, the make-up unit can also have mechanical control. Mechanically controlled water make-up is convenient where the system is small and pressure surges are regulated by expansion tanks. Losses of a small volume of water here can be compensated independently by monitoring the pressure gauge and manually opening the corresponding tap. The fluid can be supplied either by gravity or via a make-up pump. In typical gravity installations, the coolant is supplied until it flows out of the overflow pipe welded to the tank.

A key disadvantage of manual recharge management is the need to have experience in performing such manipulations, possessing certain knowledge and skills.

Expansion tank diagram

Automatic make-up valves are more relevant for large branched systems. Very often they are already “included” in the complete set of the boiler, being part of its automation.

The installation of such a device makes the operation of the heating system convenient and safe. The huge advantage of automatic recharge, like any other self-regulating installation, is that there is no need for human participation. In addition to occasional preventive checks, she does not need any additional control.

Installation of automatic feed system can be done both in horizontal and vertical position

It is worth noting that the make-up unit is used not only to add fluid to the heating system - it is multifunctional. With its help, they carry out: initial filling of the heating system with water or antifreeze, complete draining of the coolant, water treatment, pressure testing and flushing of the system.

All elements of the automatic make-up valve for the heating system must be made of quality materials: stainless steel, brass, high-strength plastic

Open heating system make-up

The signaling device for reducing the volume of coolant in an open system is expansion tank advanced design, located at the highest point of the "highway". Replenishment of the gravitational heating system of a private house is carried out with a decrease in the liquid level in the tank. Testify about the latter will be a complete lack of pressure in a special control pipe. The output of the signal pipe is conveniently installed in the kitchen or in the bathroom.

To prevent a constant flow of fluid, shutoff valves must be provided. If during the control opening of the tap water does not flow, this is a sure sign that it is time to supplement the system.

This may look like a recharge scheme for an open heating system in a private house

The feed node for the gravity heating system should consist of the following elements:

• ball valve (supply of tap water to the heating system);
• filter (purification of liquid from impurities);
• non-return valve (makes it impossible to move water from the heating circuit to the water supply circuit).

In no case should hot water from the heating system enter the cold water pipes. This can not only negatively affect the operation of the heating system, but also lead to a deterioration in the quality of drinking water. Because of what can the coolant begin to move in the opposite direction? The main reason is insufficient pressure in the supply line. An operational factor is also possible: when the shut-off valve is simply “not holding”.

You can read more about the features of the device and the principle of operation of open-type heating systems in our article:https://aquatech.tomathouse.com/en/otoplenie/razvodka-otopitelnoj-sistemy/otkrytaya-sistema-otopleniya.html

Subtleties of replenishment of a closed heating circuit

For a closed heating system, the most correct solution is to install an automatic make-up unit.If the pressure drops below the minimum level, the installation itself solves the "problem". Different types of fittings can be used in automatic units, but it is best to stay on a gearbox with a built-in filter, a check valve and a valve equipped with a pressure gauge. The manometer serves for visual control of a pressure indicator.

For schemes involving the addition of tap water, it will not be superfluous to install a full-fledged device for complex filtering of liquid from impurities

The make-up device is optimally mounted on the bypass. Having packed all threaded connections and soldered mounting valves (for dismantling, replacing or repairing valves), the assembled unit can be connected to a selected point in the heating system. To start the installation, it must be set to the desired operating pressure. This manipulation is carried out using the adjustment screw located at the top of the device. Gently spinning and controlling the indicators on the pressure gauge, you need to set the required parameter value. Then fix the screw with a lock nut.

You can learn about the advantages and disadvantages of a closed heating system, as well as the principle of operation, from the following article:https://aquatech.tomathouse.com/en/otoplenie/razvodka-otopitelnoj-sistemy/zakrytaya-sistema-otopleniya.html

Automatic recharge system example

A lot of equipment is presented on the market to solve the issue of heating systems recharge. Want to get an automatic, seamlessly functioning, reliable installation? It can be "assembled" from the following elements:

• containers with screw cap;
• metering pump;
• pressure switch;
• rigid suction line with level sensor;
• air valve for exhausting air;
• a fitting for filling the coolant into a tank equipped with a plug (prevents solid particles from entering the tank);
• an injection valve for connection to a circulation system;
• flexible tube;
• a low level sensor for signaling the absence of liquid in the make-up tank;
• an electric mixer that prevents possible separation of the coolant into fractions.

A well-assembled assembly of the above components will be highly efficient in maintaining the required pressure in the heating circuit, as well as fully compatible with the air conditioning circuit of the premises. The installation will automatically “eliminate” all regular losses in the systems: by connections, by pump seals, on valves. She is completely “not capricious” with respect to the coolant: it works well with both water and glycol-containing liquids.

The volume pump used in this automatic make-up unit is able to overcome backpressure in the system without sudden pressure surges when turned on

This node operates according to this principle:

1. Through the nozzle or the neck, water / glycol and water in the appropriate proportion / ready solution are poured into the container.
2. The feed installation pump is connected to the network and with low productivity pumps the coolant into the system, thereby ensuring its uniform filling.
3. When the pressure in the system reaches the set value, the pumping automatically stops.
4. When pressure drops, the relay switches on the pump, which returns stability to the system.

Actual picking and maintenance tips

Which feeding installation you would not choose, remember, first of all, it should be safe and convenient in operation, made of high-quality materials. If the heating system is small, give preference to a device with the simplest design. The central caliper with moving parts and the internal compensation piston must be made of materials with a low adhesive coefficient: the risk of lime formations in the assembly must be minimized. It's no secret that they are the main reason for the poor operation of the device.

Please note whether the product has a replaceable cartridge: this will greatly facilitate and speed up the process of revising the assembly for you.

Periodic maintenance of the make-up device will help to avoid malfunctions of the entire heating system

To clean or replace the entire cartridge, proceed as follows:

1. Insulate the installation.
2. Unscrew the control knob located below.
3. Unscrew the set screw and remove the cover.
4. Remove the cartridge with pliers.
5. After necessary manipulations, reassemble the device.

It remains only to reconfigure the equipment and continue to enjoy the smooth operation of the heating system in your home!