How to set the mixing valve? Everything you need to know about mixing valves!

Added: Tuesday, 3/8/2022


The mixing valve is one of the key elements used in heating installations and hot water systems. It allows you to prevent overheating and cooling of the system, and thus reduce energy losses. This is not its only advantage. What else are mixing valves used for and what should you pay attention to when installing them?

What are mixing valves and what are they used for? How to choose and install them?

From this article you will learn:

  • how mixing valves work,
  • how to choose the right mixing valve,
  • what to remember when installing the mixing valve.

See mixing valves from Afriso at the Onninen wholesaler

What are mixing valves and what are they used for?

Mixing valves - as the name suggests - are used to thoroughly mix water from two circuits. They are therefore useful, for example, when both high- and low-temperature systems are installed in one installation. Thanks to these elements, you can also combine several different heat sources - for example, a solid fuel boiler with a heat pump or a gas boiler with a fireplace with a water jacket.

The use of mixing valves allows you to improve the comfort of using the central heating system. Thanks to them, users can control the operation of the heating installation and optimize its operation. This, of course, translates into lower costs and a longer boiler life.

Valves used in central heating systems mix water heated by the boiler with returning water. This makes it possible to obtain different temperatures for individual heat zones in the building. Moreover, these devices are also used to divide the liquid stream so that it reaches both the heating system and the domestic hot water installation.

See mixing valves from Afriso at the Onninen wholesaler

What should you pay attention to when choosing a mixing valve?

What are mixing valves and what are they used for? When choosing mixing valves, you must first pay attention to their different types. Mainly available on the market are:

  • Three-way (or three-way) valves – used in modern heating installations, but also in cooling systems and utility water systems. Their task is to mix the appropriate amount of hot medium with cool water. Thanks to this solution, it is possible to quickly change the operating mode and adapt it to current weather conditions. The three-way valve is also used when combining underfloor heating with a radiator system.
  • Four-way valves – used in solid fuel boilers. In addition to the functions of three-way mixing valves, they offer an additional convenience in the form of increasing the temperature of the water returning to the boiler. The device distributes most of the medium throughout the installation and transfers the rest to the feed pump, which allows for even distribution of temperature between all radiators in the system.

It should also be noted that mixing valves are divided into manual and thermostatic:

  • Manual mixing valves have a knob that can be used to change the water proportions. Devices of this type are also equipped with a controller that takes into account factors such as weather conditions.
  • Thermostatic mixing valves operate completely independently. Regardless of the hot and cold water parameters, everything is regulated automatically. The devices strive to maintain a constant temperature, previously specified by the user.

See mixing valves from Afriso at the Onninen wholesaler

When choosing a mixing valve, you should first specify the user's needs and the specificity of his heating installation. The most important step will be to determine the purpose of this device. Depending on whether it is to power two different systems or protect the boiler against low temperatures, the contractor should choose a switching or mixing valve.

In addition to taking into account the above divisions, it is also worth remembering issues such as the quality of the device. It should come from a well-known and respected manufacturer and therefore be covered by a long-term warranty. A solid valve will be characterized by a high level of resistance and long service life, which will translate into failure-free operation of the installation.

The criterion that should not determine the selection of a mixing valve is its price. It is worth bearing in mind that high-quality products may cost more than weaker alternatives. Of course, you should use common sense . Another aspect that influences the price of the device may be the presence of an electric actuator, the size and power of which should be appropriately adjusted to the specific installation.

How to install a mixing valve?

An issue that heating system installers often wonder about is the installation and configuration of mixing valves. First of all, remember that in open systems they should not be placed on the pipes leading from the heating device to the overflow vessel. It protects the installation in the event of an increase in water temperature, enabling it to be moved outside the heating circuit. Valves must not be installed on the way to the expansion vessel either. This could damage the entire system.

One of the most frequently asked questions when installing a mixing valve is whether it should be installed after or before the pump. Interestingly, the answer depends on the type of circulation. In heating systems it is installed after the pump, and in hot water installations before it.

While it is possible to manually configure a three-way or four-way valve, choosing a model equipped with an electric actuator will provide much better results. As you already know, this function will automatically adjust the flow of liquid at the appropriate temperature.

Manual and thermostatic mixing valves in the Onninen offer

If you are looking for efficient and solid valves for your customers, buy Afriso products. They are characterized by high quality workmanship and a long warranty period. Among the models available in our online warehouse you will find both thermostatic and manual valves. You can also choose between three- and four-way variants.

Examples of Afriso mixing valves include:

  • ARV 384 ProClick DN25 three-way rotary mixing valve – characterized by a wide range of applications and used for mixing water in the heating system.
  • Thermostatic mixing valve ATM 333 DN20 – designed to regulate the hot water temperature supplied to washbasin and shower faucets.
  • ARV 484 ProClick DN25 four-way rotary mixing valve – for installation in solid fuel boilers; mixes the water and at the same time increases the temperature of the return to the boiler.
  • ATV 553 DN32 temperature valve – protecting the boiler against low-temperature corrosion, extending its life and increasing efficiency.

As you can see, in the Afriso range you will easily find mixing valves perfectly tailored to the needs of your customers. Thanks to these devices, you will guarantee efficient and reliable heating installations, resistant to costly heat losses and damage resulting from corrosion.

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