Thermostat for heated floors: principle of operation + analysis of types + installation tips

Thermal elements of a heated floor do not come into contact with the air they heat, so the temperature in the room is controlled by an external device - a thermostat.The amount of electricity consumption depends on its functionality. Agree, for an informed purchase it is worth understanding the characteristics and capabilities of the device.

We will tell you how to buy the most suitable thermostat for your underfloor heating. The article we have presented describes its varieties, which differ in the type of control, the type of temperature-fixing device and the method of installation. Tips are provided to make it easier to choose the optimal model.

The principle of operation of the thermostat

The thermostat is designed to control the operation of the underfloor heating system (WHS). It consists of a control device and one or more sensors. Information from them is taken into account when turning heat mats on and off.

Thanks to the operation of the device, an even temperature is maintained in the rooms and energy consumption is minimized.

The rhythmic switching on of heated floor heating mats allows you to save half of the electricity, which pays for the cost of the thermostat in a few months

Thermostats are easy to use and even teenagers can use them. In this case, the operating mode of the STP can be changed several times a day without fear of breakdown or premature failure of the equipment.

The minimum temperature can be adjusted separately for each room. In addition, some models allow programming of the device’s operating mode during the day.

Types of devices by type of control

The operation of the STP is regulated by a special device, which is usually hung on the wall. It has the dimensions of a standard rocker switch and can be equipped with a mechanical, electronic or programmable interface.

Mechanical without electronics

A mechanical thermostat does not include electronic components in its design. Electrical wires to the STP go directly through the device, which adds problems during its installation.

Mechanically, the thermostat usually has a limit switch. It allows you to quickly turn on/off the device without having to change temperature settings

The function of a temperature sensor in a mechanical regulator is usually performed by a bimetallic plate, which, when cold, closes the contacts of the heating mats. As the temperature in the room increases, it bends and disconnects the electrical circuit, as a result, heat generation stops.

The regulation interface is represented by a wheel, by rotating which you can adjust the temperature in the room.

This device design has its advantages:

1. Low price.
2. Easy to use.
3. Ability to work at low temperatures.
4. Reliability.
5. Independence from voltage surges.
6. Long service life.
7. Automatic switching on after a power outage.

The simplicity of a mechanical thermostat also causes its disadvantages, which can be critical:

1. Minimal functionality.
2. Lack of remote control capability.
3. Large error.
4. The presence of clicks when bending the bimetallic plate.

Despite their simplicity, mechanical thermostats have a strong hold on the consumer market due to their high reliability, simplicity and interchangeability.

With electronic mechanism

Appearance of electronic thermostats for electric heated floors may not differ from mechanical devices. The main difference lies in the internal filling of the device.

Mobile thermostat units are usually battery-powered, so their displays are not backlit. Setting up such devices in a dark room is difficult.

Electronic floor heating controllers consist of the following components:

1. Frame.
2. Control microcircuit.
3. Built-in or external temperature sensor.
4. Electronic key for turning on and off the power supply to heating mats.

Temperature adjustment in electronic thermostats can be done using a touch display, buttons, an adjustment wheel, or a combination of these methods.

Some models support multi-zone temperature control, in which several isolated heated floor zones with their own sensors are independently connected to the control microcircuit.

The advantages of electronic devices include:

1. Possibility of installing a remote temperature sensor in any location in the room.
2. Availability of a display showing the current and set temperature.
3. Possibility of multi-zone heating control.
4. Temperature sensor accuracy up to fractions of a degree.
5. Indication in case of error or breakdown.
6. Possibility of completing with an external remote control unit.

The disadvantages of an electronic thermostat are mainly due to the presence of a microcircuit.

Thermostat models are not tied to specific manufacturers. During installation, the devices can be combined with heating mats and sensors from various companies

The disadvantages include the following characteristics:

1. Dependence of the stability of the control microcircuit on voltage drops.
2. Failures in settings during a short-term power outage.
3. Higher price than mechanical devices.

Mechanical thermostats are only 15-25% cheaper than their electronic counterparts, therefore, in the absence of voltage drops in the network, the choice between these two types of devices is determined mainly by their appearance.

Great looking luminous displays are often the main motivating factor when purchasing a particular thermostat model.

Programmable electronic devices

The main difference between programmable thermostats and conventional electronic devices is the expanded functionality of the control microcircuit. This type of device allows you to set different temperatures in the rooms depending on the time of day.

As a result, users benefit greatly from energy savings by reducing the heating of the air in an empty home.

The cost of a programmable thermostat directly depends on the quality of the display and the number of parameters that the device operates in its operation.

Programmable thermostats may also have a remote control function from a smartphone via Wi-Fi.

The disadvantages of such devices include the high cost and difficulty of setting up in the absence of skills in handling the equipment. Otherwise, the pros and cons of programmable thermostats are the same as conventional electronic ones.

With remote control unit

In electronic and programmable thermostats, internal components can be divided into two blocks: main and mobile. Electrical cables are connected to the main box and wired temperature sensors are connected. It can be located in any remote location of the room, which facilitates installation work.

Some manufacturers of programmable thermostats produce their own applications for smartphones, by installing which you can configure the equipment from your gadget

A battery-powered mobile unit is used as a control panel. It can lie on a table or hang on the wall. Additionally, the consoles can be equipped with external temperature sensors that measure the ambient air temperature. Such devices are convenient because they allow you to hide the adjustment mechanism from small children.

Types of temperature sensors for underfloor heating systems

The operating mode of STP heating elements directly depends on the correct temperature measurement by temperature sensors. They can be built into the body of the control box or placed remotely.

Thermal sensors come in four types:

1. To determine air temperature.
2. Infrared, measuring the heating of the floor surface from a distance.
3. To determine the temperature of the floor surface by contact method.
4. Combined.

The air heating sensor is usually built into the thermostat or its mobile unit. It is used when the heated floor is the main heating system. The main requirement for its location is the presence of natural air circulation around the device.

The tips of temperature sensors should be made of materials that conduct heat well, then the speed of the thermostat’s response to excess heat will be higher

Infrared floor temperature meters can be built into the thermostat housing or placed as a separate unit. The main requirement for their installation is that there are no obstacles between the sensor and the floor. The distance between the device and the surface to be analyzed must be at least 30 cm.

Contact-type temperature sensors look like a long wire with a thickening at the end.On the one hand, they are connected to the thermostat unit, and on the other, they are placed in a special long corrugated pipe under the floor. This installation feature makes it easy to replace a broken sensor with a new one.

The advantage of underground placement is the possibility of multi-zone control of floor temperature within one room. Typically, such sensors are installed when installation of heated floors as an additional heating system.

Several sensors can be connected to the thermostat, but this scheme is used mainly within the framework of an integral set of equipment.

Rules for installing a thermostat

Electrical cables and wiring from temperature sensors must be connected to the thermostat hung on the wall. To do this, appropriate grooves are made in the slab - grooves. In them, wires are laid to the electrical panel and to the floor.

The floor temperature sensor must be as far from each other as possible from adjacent heating elements, otherwise when they are turned on, it will immediately trigger and disconnect the electrical circuit

If the equipment is installed in a room with high-quality interior finishing, then you can use overhead devices and run cables over the walls in boxes.

The following are the basic rules that must be observed when installing thermostats:

1. It is better to place the adjusting device at a distance of 40-170 cm from the floor, unless otherwise provided in the instructions. If you have a mobile control panel, the main box can be installed in any convenient place.
2. The main functions of the floor temperature sensor are to prevent overheating of the floor covering and foot comfort, but not to control the temperature of the air in the room.
3. In damp rooms, it is permissible to use thermostats with appropriate protection against water ingress.
4. When the device is built into a wall, a mounting box made of non-combustible materials is used.
5. Wires from the regulator to underfloor heating heaters with a power of more than 1 kW must be routed in hollow heat-resistant tubes.
6. The floor temperature sensor should be located between the heating elements and at least 50 cm from the walls.
7. When turning on the device for the first time, it is necessary to take into account the minimum operating temperature specified in the instructions.
8. Wire connections to the thermostat terminals must be made exclusively according to the diagram specified in the manual.
9. Installation of the thermostat begins only after the heating elements are finally laid on the floor in order to correctly calculate the length of the wires.
10. When filling the floor with solution, it is necessary to well insulate the end of the tube with the temperature sensor.
11. Before pouring the solution onto the floor, it is necessary to check the functionality of all elements of the system.
12. Heating mats must be grounded, and an RCD is installed in front of the thermostat.

Compliance with these rules will protect residents from electric shock, the house from fire, and equipment from premature failure.

Tips for choosing devices

When purchasing a thermostat, you need to know certain nuances in order to pay only for the necessary functions and ensure longevity of operation. floor heating system and the device itself.

When choosing a thermostat, you should pay attention to the quality of the plastic case. If the manufacturer saves on this, then it is worth thinking about the reliability of internal components

These selection features include the following rules:

1. For heating small rooms, an inexpensive mechanical or electronic thermostat with an internal air temperature sensor is suitable.
2. It makes sense to buy a programmable thermostat if you need multi-zone temperature control, as well as to save energy when there are no residents at home during the daytime.
3. The thermostat must correspond to the maximum power of the heating elements with a margin of 25-30% in case of operation at reduced voltage.
4. For houses with wooden interior decoration, only overhead thermostat boxes are suitable.

Also, when choosing a device, it is necessary to take into account its design.

The existing model range allows you to buy not only reliable equipment, but also a thermostat that will fit perfectly into the interior of the room.

Conclusions and useful video on the topic

Videos with reviews of types and examples of installing thermostats will allow you to better understand their operating principle and selection criteria.

Video #1. Classification and principle of operation of thermostats:

Video #2. Detailed settings of a programmable thermostat:

Video #3. Installation of a temperature sensor in the floor:

Analysis of various thermostats allows us to say that their maximum functionality is not always justified from both a financial and operational point of view. Therefore, this equipment must be selected for each STP separately.

How did you choose, attach and connect the thermostat for the underfloor heating system? Share what became the decisive landmark for you? Please leave comments in the block below, ask questions, post useful recommendations and photos on the topic of the article.