To heat country cottages today they often began to use underfloor heating. Some owners prefer to heat the rooms separately in this way, while others, on the contrary, mount a similar system throughout the house.
In some cases, these decks are combined with radiators, which require a lot of warm water to function properly. To ensure such uninterrupted operation, you will have to make mixing units with your own hands.
What are they needed for?
Mixing units are used only when water acts as a coolant. The principle of operation of this heating system is quite simple:
- Boiler.
- Fluid for the transfer of thermal energy.
- Heating circuit for underfloor heating and radiators.
It is recommended that the temperature of the heat carrier in the batteries be 95 ˚C, and in the "warm floor" system - about 31 ˚C. Thus, it will be possible to create comfortable living conditions. Although when choosing the temperature of the coolant for the floor, the type of coating and the thickness of the heating cake should be taken into account. If necessary, it can be raised to 55 ˚C.
The boiler gives out too high a temperature that does not correspond to the technical capabilities of underfloor heating, which is why a mixing unit is installed. It is equipped at the entrance of the coolant to the water heating system. Thanks to this device, the hot liquid is mixed with the cooled one, as a result, a temperature balance is observed. In addition, the mixing unit for underfloor heating prevents possible damage to the heating system.
By the way, if a water heater is used that boils water only up to the maximum allowable temperature, it is not necessary to mount mixing units. But when the boiler functions to heat the coolant and is equipped with a separate heating circuit, such a device will have to be equipped.
The principle of operation of the mixture
This equipment consists of the following elements:
- valve. It works when too hot liquid comes in.
- Special pump. Its main goal is to increase the pressure in the pipes and uniform heating.
- bypass. This device protects the water heating system from overloads.
When installing a pumping and mixing unit for underfloor heating on your own, it is important to have an idea of how it functions in order to avoid mistakes. Such a device works according to the following principle. First, the liquid coming from the boiler lingers in the collector, if it is very hot, then a special valve stops it. Then, under pressure, the damper opens, after which cold water begins to flow from the return pipe. When the temperature returns to normal, the valve rises and passes the coolant. 
Types of admixtures depending on the valves used
Mixing units must always be mounted up to the floor contour. And you can fix them in any room where a special mixing cabinet is provided, even in the room that you heat. Today, two types of mixers are installed: a two-way or three-way valve.
Features of the two-way valve
Such a device is often called a power supply. The thermostat installed on it is equipped with an infrared sensor that analyzes the temperature of the liquid entering the warm floor. The head of such a device closes and opens the valve, prohibiting or allowing the supply of hot coolant.
The mixing of liquids of different temperatures is carried out in this way: the water that flows through the system does it cyclically, in a circle. The safety head closes or opens the valve, adding hot coolant or prohibiting its supply. Most experts recommend installing a mixture with a two-way valve in the water floor. However, it should be remembered that it is better not to use this type of crane if the heating area exceeds 200 square meters. 
Benefits of a three-way valve
This mechanism regulates the temperature of the water heating in the collectors by mixing the hot liquid supplied from the boiler and the cooled liquid that has passed the underfloor heating circuit. In such a valve, a large damper is installed, which acts as a bypass, thereby protecting the underfloor heating system.
True, if the temperature sensor or other thermal control equipment breaks down, then too much hot coolant will be supplied through the damper in the water heating, which can cause the entire system to fail.
The main advantage of a three-way valve is the ability to connect additional devices, for example, remote or mounted temperature sensors. Such devices are able to automatically maintain the set comfortable temperature, regardless of the weather conditions outside.
Mix assembly
To build a mixing unit with your own hands, you must first prepare the necessary parts:
- Cap nuts.
- Safety two-way or three-way valve.
- Nipples.
- Thermometers.
- Circulation pump.
- Check valve.
- Ball valve.
- Manual air vent.
- Triplets and more.
The assembly technology of the mixing unit is reduced to the installation of thermometers. They are mounted in the return and supply valves. They are necessary to regulate the temperature of the coolant. A safety valve is used as a thermostat, which turns on mixing when the degrees exceed the established norm.
The pump in such equipment maintains uniform heating of the coolant in the pipeline due to its circulation and pressure increase. Installing a bypass will allow you to control the temperature, protecting the underfloor heating system from overloads. An important role in the mixing unit is played by the water drain filling valve. It will not break passing pipes if the water pressure exceeds the norm set by the owner of the house.
After the mixing unit for the warm floor is assembled with your own hands, you should connect it with fittings to the circuits. But before starting the system, it is necessary to carry out balancing so that there is a uniform temperature throughout the underfloor heating substrate. 
How to properly install a heat-mixing unit?
A self-assembled submix is equipped to the contour of the underfloor heating system. Mounting can be right or left handed. If suddenly the appearance of the equipment does not fit into the interior, it is better to disguise it.
The first step is to install the pump and the temperature sensor on the inlet pipe. Then a mixing valve must be connected to the warm pipe, and a check valve to the outlet. In small rooms, it is not necessary to mount the collector group to the circuit with batteries.
After that, the outlet of the valve for the return is connected to the cold pipe and diverted to the mixing one. To check the temperature in the underfloor heating, a test run is carried out. 
Connecting a warm floor to a water heater
Such a system is connected to the boiler according to the scheme, depending on the type of floor heating - one- or two-pipe. For example, in a one-pipe heating system, the bypass must be open all the time, while in a two-pipe heating system this is not necessary. 
Moreover, the connection scheme can be both simple and using additional elements. One way or another, valves, thermostats and flow meters will have to be installed for each group of collectors.
