How long does a warm floor warm up when you turn it on for the first time

Room temperature control

To determine what temperature of the warm floor will be at one point or another in the room, allows individual temperature control. For this it is used:

Room automation. In this case, it is mainly not the temperature of the warm floor that is regulated, but the air in the room.
Zone automatic systems with a sensor installed at a specific point of the heated floor. These systems more allow you to control the temperature of just the floor, and the indicators in the air are regulated depending on it.

Wiring diagram for underfloor heating thermostat

Naturally, the owners of residential premises are more interested in the question of what temperature to set on a warm floor than in general issues of regulating the temperature regime in a room. There are some nuances here. For example, some homeowners, in order to quickly heat the floor in a particular room, try to bypass the automation and begin to manually regulate the system by opening and closing the valves, as a result, the circuits of this heating system become unbalanced, which leads to its failure.

To prevent this from happening, you need to decide once what temperature of the warm water floor you need, and patiently wait for the automation to bring it to the desired level. In this case, in no case do you need to upgrade it yourself, since the automation of one manufacturer is not combined with devices and devices from another manufacturer. In any case, even if you have "group" climate control in the room, you will have to install thermostats for room temperature control in it, since only they are able to maintain it in optimal condition.

The main link in home floor heating systems is a thermostat and a servomotor. The thermostat controls compliance with the optimal temperature values, and the servomotor regulates the flow of coolant into the system. Thermostats are usually mounted on the interior walls of rooms at a height of about 0.5 m from the floor. It is forbidden to install such sensors on external walls, behind furniture and curtains, close to heating devices.

Local temperature control in the loops is carried out using thermostats

At the same time, only one servomotor will work with such a valve. It is he who, at the command of the thermostat, will regulate the temperature readings in your room.

That's all for now, read the continuation in the next updates of our online magazine "So they lay the floor." Good luck with your repair ladies and gentlemen!

Film image floors

They have different heating parameters. The canvases are available in various sizes. If it is necessary to insulate a room that is large, then it is recommended to use canvases with a large width (from about 1 meter).

The device for regulating the heating temperature will have to be purchased separately. Its power should be calculated. The energy consumption of 1 square meter of film is approximately 150 watts. Next, take the floor area and multiply by 150.

It is required to install infrared type film by cutting off the edges of the material. You need to isolate them. It is necessary to install a sensor that controls the heating. It is placed in a recess located under the film itself.

It's important to capture it. We place the electrical cable under the tile

To prevent the coating of the film image from shifting, it must be fixed with adhesive tape (to the base).

The next step is to install the temperature controller. It should be installed close to electrical wiring. It is mounted in a permanent place. It is required to lay electrical wires, we connect them in parallel. The wires can be hidden under the plinth or a plastic decorative cover can be installed.

Heating without batteries. 06/28/2015 1500

Water heated floor temperature.

The surface temperature of the warm floor ranges from 25 to 30 degrees. And the human body temperature is 36.6 degrees. That is, a person either does not feel heat at all, or feels it a little, again within the limits of comfort. When you take off your shoes and stand with your feet on the warm floor, it is really warm, but after 15 minutes you get used to it and you don’t feel it at all.

According to Russian building codes, the temperature of the floor surface in places of permanent residence of a person should not exceed 26 degrees, and from places of infrequent stay (distance near walls, corridors, utility rooms, etc.) - 29 degrees. But the European norm of the same parameters is 29 and 33 degrees. Since the edition of SNiP according to these data has not changed since Soviet times, most developers and owners prefer to focus on European standards.

How does underfloor heating work?

Let's start with heating and supplying water (you can also fill in "antifreeze" - pipes, fittings and other fittings are designed for this, but you need to see if the boiler manufacturer allows the use of antifreeze). Water heated by the boiler to 30-40 degrees is supplied to the heating system. Underfloor heating is a low temperature heating system. But keep in mind that not all boilers can immediately prepare a low coolant temperature, for example, solid fuel or gas (except for condensing ones), so the temperature will need to be lowered using a pump-mixing unit (autonomous circulation group) mixed with cold liquid returning from the system.

Then the heated water circulates through pipes laid in the screed. First of all, everything that surrounds us in the room is evenly warmed up, then the main part of the air warms up. The advantage here is that we feel heat evenly from all sides, although to the touch all objects and walls seem cool.

Heated floor covering.

The most ideal flooring for underfloor heating is ceramic tile. It conducts heat very well. Other coatings are also used, such as laminate or engineered board (the same parquet, but it will not dry out). Cork has a low thermal conductivity, as does carpet. You can use them!

Be sure to pay attention to the labeling of products, usually manufacturers put the “warm floor” icon on the packaging. In these coatings, the necessary humidity, so that the material does not dry out, as well as the absence of harmful fumes during heating

Is there enough water floor heating for a comfortable room temperature? How to understand?

Let's go back to physics. One square meter of a heated floor gives the room 11 watts of energy, for every degree of temperature difference between the floor and the air. If the floor temperature is 28 and the air temperature is 20 degrees, then: (28-20) * 11 = 88 W / m2 per hour.

What do we do with these numbers now? This value must correspond to the heat loss of the room, otherwise the floor temperature must be reduced or added.

The heat loss of the room is calculated depending on the thickness of the walls of their composition, the area and thickness of the windows, as well as the roof and other structures. If you have a very cold house, it will be very expensive to heat it by any option. But for well-insulated and moderately insulated - a water-heated floor for heating without radiators, even in the coldest weather - is more than enough. This is evidenced by a large number of ready-made houses / warehouses / car dealerships / warehouses / shopping centers / swimming pools with a “Water heated floor” heating system.

Benefits of underfloor heating

minimum convection. No circulation of dust and other substances, as with radiator heating. The best option if there are allergy sufferers in the house.
Uniform warmth. There is no cold or warm place in the room, the whole room is heated evenly.
Pleasant warmth. Comfortable sensations associated with a direct warm flow affecting a person.
Warm air does not accumulate near the ceiling.The distribution of heat for human health is the most correct, as the saying goes, "keep your feet warm and your head cold."
Designer space. All heating is hidden, no protruding pipes and heaters.

Of the shortcomings, only large inertia can be noted, i.e. the screed heats up for a long time and cools down for a long time, it will not be possible to turn off the heating completely for half an hour or an hour. But this also has its advantage. If gas and electricity are turned off during the heating season, the room will not cool down quickly, and in well-insulated houses the temperature will drop by only 1-2 degrees in 10 hours at a temperature of -20 outside (tested on myself), which allows you not to install a backup system.

Tips for installing and operating an electric heating system

When installing a heating cable, we focus only on the area that is not occupied by furniture (such a heating system can disable a refrigerator, dishwashing machine, washing machine); It is important to calculate the length of the electrical cable as accurately as possible (it cannot be reduced). Therefore, it is better to reduce the figure obtained during the calculations in advance; To check the operation of the cable, it is better to use resistance

It cannot be turned on until it is laid. The cement and adhesive solution must dry; The surface for laying the cable must be cleaned of dust (an industrial-type vacuum cleaner gives a good result); Do not walk on the heating cable with hard shoes. This can damage him; When placing a temperature indicator (sensor), please note that it must be placed in a corrugated tube (so that the solution does not get on it). Provide for the possibility of replacing it (if it fails); Be sure to measure the resistance before installing the floor. Also take measurements after the work is completed. Check the conformity of the received data with the manufacturer; Draw a diagram according to which the floor laying operation took place (indicate the exact distances to the wall, window, door). This will come in handy when carrying out further repairs; Do not leave pockets of air around the heating cable. You can not save the solution, because this can lead to overheating. The cable will fail before work begins; You can not turn on the system immediately after the installation work is completed. You should wait 2 or 3 weeks for the cement to harden well.

In order to increase the service life of such a system, it is necessary to strictly comply with the requirements for the installation and maintenance of the "warm floor" elements. Accurate measurements of the necessary equipment are needed. It is recommended to purchase only high quality materials.

Insulated floors of the electric type can be installed independently, but it is better to entrust such work to a competent specialist. Given his experience, he will take measurements with maximum accuracy, which will allow you to purchase materials in the right quantity. Correct and competent installation guarantees a long service life of the entire system.

Criteria for choosing a heating system for underfloor heating

Temperature. Floors with tiles can heat up to 30 degrees. This factor depends on the heat loss of the room;
Room type. The greatest application was found for laying in rooms with high humidity (kitchen, bathroom, toilet, hallway, corridor). Dries water very well.
Rooms. Such floors can be used because there is a wide range of colors for tiled floors (you can choose the color of the interior);
Power. For dry-type rooms, power is sufficient up to about 130 watts per square meter, and for rooms with high humidity up to 180. This difference is due to the fact that with high humidity the floor is always colder. Therefore, more power is needed to maintain the set temperature;
Material. Floor coverings that use heating elements located under the tile tiles perfectly retain heat.

Best Answers

Andrey Fedorov:

As a specialist in the field of electric "warm floors", I can say that systems based on mats (termomat), installed directly into the adhesive layer under the tiles, warm up faster than those installed in the screed, in about 4-8 hours. But the point is different. Warm floors with a thermostat are installed for permanent use in a residential area, i.e. after connecting the thermostat, the temperature necessary to maintain the temperature is set on the thermostat, according to those. conditions, the "new floor" must enter the "working" mode of operation in a day and subsequently be constantly turned on in order to maintain the floor temperature set by you. The thermostat turns off only with the onset of the warm season or with a long absence of residents in the house (like an ordinary electrical appliance). bodies - 36.6 degrees. , and the floor is heated on the surface, usually up to 24-28 degrees (comfortable heating).

MikLaren:

The first inclusion: from 6 hours to a couple of days. I forgot to add: the heating time also depends on the voltage level in the network.

Valery:

If the floor was turned on for the first time, then for a long time 4-6 hours, provided that the work on connecting the thermostat and installing the underfloor heating sandwich is done correctly, i.e. there is a heat shield, a heat insulator and the thickness of the mortar with tiles does not exceed the calculated values

The location of the temperature sensor in the floor at the right distance from the heating elements is also important. By the way, is the heating indicator on? That is, - the floors are definitely included? There will be questions - write

Unknown:

tell everyone, tell me, I bought a dozen 16 valves, but the engine warms up for a long time, the reason is the thermostat is new

Zhenya Eremenko:

Good article about underfloor heating -

elena and alexey:

hello everyone put the floor of the electric cable in the screed connected the thermostat at night warmed the floor cold indicator lights up red! tell me what it could be!?

Optimal temperatures

In principle, the question of what temperature should be at the warm floor is regulated by SNiPs. Such regulation is due to the fact that too warm floors can lead to fatigue of the body and its overheating. The task of this heating system is to increase the level of comfort at the floor, making the indoor climate optimal for the human body.

Underfloor temperature sensor

Even if the system installed in your home is able to heat up above these indicators, you should not exceed them, since they are prescribed in the sanitary and hygienic rules.

It is worth focusing on the above indicators when deciding what is the maximum temperature of a warm floor. The physiological characteristics of the human body are such that temperatures above + 31 ° C are no longer perceived by a person as acceptable. In addition, SNiP 41-01-2003, clause 6.5.12 establishes requirements for the average temperature for various categories of citizens.

Minimum and maximum floor temperature

For example, to understand what temperature of a warm floor should be in residential and non-residential buildings, the following information will help you:

for rooms with a permanent mode of stay of people - 26 ° C;
for those rooms in which people should not be constantly - 31 ° C.

In addition, when deciding what temperature to set on a warm floor, it is worth remembering the technical requirements put forward by floor covering manufacturers. For example, at a temperature of +30°C, the lacquer coating on classic parquet can be destroyed. It can even deform due to heat.

Temperatures above +31°C are no longer perceived as acceptable by humans

If we take a laminate, then for it the maximum temperature indicator is + 27 - 29 ° С. In any case, when purchasing a parquet board and a laminate for installation on top of a warm floor, it is necessary to check with the sellers the temperature limit set for this product,as well as the ability to work together with a warm water floor. As for the tile, because of its technical characteristics, it can work at almost any temperature “issued” by a standard heating system, and here the question will already be raised about the comfort of a person being on such a hot floor.

Types of warm floors

Three types of underfloor heating are best known today:

warm water floors;
cable floor heating;
film infrared heating.

Warm water floors

Water floors are a piping system connected to a gas boiler through a manifold block. The boiler, by supplying hot water, “forces” the floor coverings to warm up.

Pipes for the water system are used from cross-linked polyethylene, polyurethane, metal-plastic and copper. The most popular pipes are made of cross-linked polyethylene. Polyurethane products require the use of special welding equipment for installation.

Warm water floors are hidden by cement screed. How long the floor coverings will warm up depends largely on the thickness of the cement screed. Pipes for underfloor heating are usually used with a diameter of 16 mm. This size, confirmed by the accumulated operating experience, is determined on the basis of thermal engineering calculations.

Through the collector unit, a certain number of heating circuits located in several rooms are heated with hot water.

Heat engineers recommend making the length of the 1st circuit about 70 m with a pipe diameter of 16 mm. The height of the screed is advised to perform no more than 50 mm. In this case, the thickness of the screed over the laid pipes will be about 30 mm.

How much does a warm floor warm up when it is first turned on under such conditions?

Practice shows that the heating time of a warm floor at the first start can last from 12 hours to one and a half days.

To do this, the water leaving the boiler is brought to a temperature of 90°C.

After the floor warms up, the initial temperature of the coolant is reduced to 70 ° C.

Cable floor heating

Cable laying is performed in the form of a spiral and a snake. The spiral shape is used in small areas (up to 20 m2). On large bases, the cable is fixed in the form of a snake.

The electric heating element will quickly heat up and begin to give off heat to the body of the floor. A screed thickness of 70 mm or more will significantly increase the inertness of concrete. The floor in this case, as long as it takes to heat up, it will slowly cool down. At the same time, power consumption will increase significantly.

How much heated floors warm up when the cable is first turned on depends largely on the power of the wire.

With proper installation of electric heating and compliance with building codes when laying the screed, the time for the first warm-up of the base of the room can be from 6 to 8 hours.

Film infrared heating

The increasing attention of consumers is attracted by film infrared heat-insulated floors. In the polymer layer of the film, an electrode grid is soldered, which, under the influence of an electric current, emits thermal rays in the infrared range.

Many people are interested in how quickly the floor covering from the IR film heats up. This question cannot be answered unambiguously. It all depends on the coverage area, the technical parameters of the IR film, the method of laying the connection scheme to the electrical network. But one thing can be said, that where the floor was heated under the IR coating, the time of the first heating was 2-3 hours.

Due to its design features, IR coatings are easily and quickly mounted under any floor covering, except for ceramic tiles. The exception is the IR heating device under the tiles. For more information on connecting and heating the floor, see this video:

Benefits of underfloor heating

The room heats up evenly;
Can be used as part of a completely independent heating system;
It is possible to connect to the heating plant;
Mounted only once;
No maintenance required;
Profitability.

But, such a system is difficult to install. Additionally, a water pump is required. If there is a breakdown, then a comprehensive repair of the entire system will be required. Pipes for such a floor are made of a material called "metal-plastic", so they do not collapse from corrosion. A special device inside the pipes prevents the accumulation of accumulations, so the diameter of the pipes inside is maintained.

underfloor heating installation

Installation of such a floor requires special skills, knowledge, experience and skills. Expensive installation is cost-effective only for providing heating in rooms with a large area. The most successful solution would be to install an electrically insulated system. The most effective solution was the use of a cable with two cores.

The floor is not warm enough. Low coolant temperature

A typical and common problem that owners of city apartments and private houses have to face when complaining about the unsatisfactory performance of a warm floor is uneven heating. During normal operation, the water circuit must completely and evenly heat the concrete screed or floor covering, creating the necessary conditions for heating the home.

In this case, the problem is the uneven flow of the coolant along the water circuit. Due to the fact that pipelines can have different lengths, due to the same heat carrier supply intensity, the degree of heating of each pipe is different. Usually, before starting in the collector cabinet, the levels of the electric drives are set to the required position.

Before starting the system, the optimal parameters calculated for each circuit are initially set. By measuring the temperature of the coolant in each water circuit, the actuators are set to the appropriate position. Consequently, the heating temperature of the coolant in the system changes, and the degree of heating of the water circuit also changes.

The way out in this situation is as follows. We are looking for a water circuit in which the coolant does not heat the water floor in accordance with the set temperature, then manually increase the flow of boiler water.

Sources

http://GuruPola.ru/teplye-poly/skolko-progrevaetsya-pri-pervom-vklyuchenii.html
https://eurosantehnik.ru/ne-rabotaet-ne-greet-vodyanoj-teplyj-pol.html
http://stroim42.ru/2018/09/07/%D0%B2%D1%80%D0%B5%D0%BC%D1%8F-%D0%BD%D0%B0%D0%B3%D1% 80%D0%B5%D0%B2%D0%B0-%D1%82%D0%B5%D0%BF%D0%BB%D0%BE%D0%B3%D0%BE-%D0%BF%D0% BE%D0%BB%D0%B0-%D0%BF%D0%BE%D0%B4-%D0%BF%D0%BB%D0%B8%D1%82%D0%BA%D1%83/
http://teplo-svetlo.ru/%D1%82%D0%B5%D0%BF%D0%BB%D1%8B%D0%B9-%D0%BF%D0%BE%D0%BB-%D0 %BF%D0%BB%D0%BE%D1%85%D0%BE-%D0%B3%D1%80%D0%B5%D0%B5%D1%82-%D0%BF%D1%80%D0 %B8%D1%87%D0%B8%D0%BD%D1%8B-%D0%B8-%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D1 %8F
http://netholodu.com/teplyj-pol/vodyanoj/neispravnosti.html
https://ZnatokTepla.ru/teplyj-pol/pochemu-ne-greet-teplyj-pol.html

Fundamentals of climate control

After we have found out what temperature of the warm floor is considered optimal, it makes sense to deal with the methods of its regulation. Currently, this process is usually carried out using automatic control systems. Such a system includes a set of sensors and automatic valves controlled by a remote control.

The big advantage of using automation for underfloor heating is the fact that once you set the microclimate values you need in your room, you may not return to them for several days, as they will be maintained automatically. The manual control method implies constant manual adjustment of all necessary parameters, which is inconvenient and time consuming.

As for the classification of such automatic systems, depending on the place of their installation, the main tasks performed by them, as well as the method of direct control, the automation of a warm water floor is divided into:

zonal or individual;
group;
complex.

Under the group regulation of indicators of a warm floor is understood the general control of indicators of temperature in the room, created by the heating system. To date, there are several ways to set the same temperature at several points in the room:

Thermostat for electric underfloor heating

its regulation directly on the heat source using built-in controls and controls;
regulation on mixing units of group type;
regulation on mixing units of individual type;
application of the "constant" principle using a thermal head equipped with a thermal sensor, which is mounted on the mixing valve;
the use of "climate control" implemented with the help of programmable heat supply controllers.

From a technical point of view, the temperature here is controlled by setting the desired value on the thermostat. Upon reaching it, the sensors transmit a signal to the control panel and valves with servo drives start or, conversely, remove the coolant from the system, thereby regulating its temperature.

Installing a temperature sensor for underfloor heating

Diagnosis of breakdowns of the electric floor

A malfunction of underfloor heating can lead to a complete failure of the equipment or a decrease in its efficiency. In the first case, you can start diagnosing immediately. In the second, you first need to objectively evaluate the operation of the system. The fact is that apartment owners often overestimate the ability of electric underfloor heating to heat a room . As a result, they feel that the system is not working efficiently enough.

If it doesn't heat up to its full potential

To objectively evaluate the operation of an electric floor, note the time it takes to heat up and compare it with standard values:

Comfort from the film floor without screed and adhesive layer begins to be felt after 10 minutes of system operation;
Matte floors in the adhesive layer are heated to the temperature set by the thermostat in 6-8 hours;
Cable underfloor heating under a thick screed warms up for a day.

If your floors fit within the specified norms, then there are no problems. It may seem that the surface is not warm enough, due to the difference in body temperature (36.6 ° C) and the one that is set on the thermostat (20-30 ° C). The task of the electrical system is to heat the floor and air to a temperature comfortable for a person, and its average value is only 21 ° C.

If the electric floor heats up to the operating temperature for too long or cannot reach it at all, then at least one of the reasons takes place:

The thermal sensor is installed too close to the heating element. When the set temperature is reached, it causes the thermostat to turn off. But since the heat has not yet reached the flooring, it remains unheated;
Sensor failure. Check the voltage at the terminals of the heating element and at the power supply without turning off the thermostat. The readings must be the same. Additionally, check the resistance of the sensor, which must match the value indicated in the temperature controller's passport;
Low voltage. Can be checked with a multimeter. The voltage is measured at the terminals marked L and N. Before measuring, the thermostat must be removed from the socket. If the voltage is less than necessary. That the problem is found;
No thermal insulation layer. The heat loss can be so great that your floor will never be able to warm up. Remember, when installing the system, you used heat-insulating reflective materials. Did you follow the rules for their use? This is especially true for owners of apartments on the ground floor;
Power calculated incorrectly. If the calculation of the warm floor is incorrect, it will not heat well.

From the list of possible causes of poor floor heating, it can be seen that most problems can be avoided at the stage of calculating and laying the electrical system. Noticed errors made during installation are easier to correct before finishing with a top coat. And if a screed has already been installed and tiles have been laid, then the repair of an electric underfloor heating promises to be long and costly.

If not warm at all

If the electric floor does not heat at all, then you need to carry out diagnostics in the following order:

Check for voltage.The floor completely stops heating only when it is completely absent. If there is power, then go to step 2;
Check the sensor by measuring its resistance. If it is defective, it will have to be replaced. Otherwise, go to step 3;
Check the operation of the temperature controller. Replacing it is the easiest and cheapest way to repair floors. If it's OK, go to step 4
Check the resistance in the circuits using the same multimeter. If it does not correspond to the values \u200b\u200bspecified in the passport, then you will have to look for short circuits or cable breaks.

If the sensor and temperature controller are working, and there is voltage, but the floor still does not heat, then it will need to be repaired. In order not to dismantle the entire cover, a special tool is needed for troubleshooting. This is especially true if the mat or cable is embedded in a screed, the installation of which is a laborious and expensive task.

Features of floor heating when first turned on

When the required temperature is reached, underfloor heating maintains the necessary minimum heating to maintain it.

Why is there emphasis on the expression "first inclusion"? The answer to this question is not difficult. When the underfloor heating system has heated up to the desired temperature level, the heating of the base of the room is not turned off completely as needed, but the minimum heating level is maintained.

This is done in order to reach the maximum level of floor heating in a short period of time at any time.

The first inclusion of a warm floor requires much more energy than during operation. Therefore, it will take a lot of time. Additional energy and time are needed to overcome the inertia of the screed.

It should be noted that for IR heating there are no problems of overcoming the inertness of the floor structure.

Knowing what temperature of a warm floor is considered optimal is the direct responsibility of the homeowner in whose house a similar heating system is installed.

The fact is that only the optimal setting of its automation will allow creating a pleasant microclimate in the premises. In addition, building codes and regulations establish fairly stringent requirements for this indicator, which are not recommended to be violated.

When setting up thermostats directly, you must always take into account different circumstances. For example, when answering the question of what temperature of a warm floor under a tile will be optimal, it is necessary to take into account the fact that a ceramic tile is felt by a human foot as a colder material than, for example, a laminate. Therefore, when setting the temperature readings for a room with such a floor, they must be slightly overestimated.

Underfloor heating is the most convenient type of heating, in which there is a uniform heating of the air.

How much does a warm floor heat up when you turn it on for the first time

We will not give formulas for calculating the heating of electric floors below, you can see this in any textbook. The reason is that the calculation formula contains variables that are very difficult to calculate in everyday conditions. So, let's begin.

When you first turn on the electric underfloor heating, it will warm up from 15 minutes to 12 hours. What does it depend on?

up to 15 minutes - if you have an infrared warm floor (often called an infrared film) and the installation was directly under the floor covering itself (under a carpet, rug or carpet). You will immediately feel warm. Cons: Heats up quickly and cools down quickly.
up to 30-60 minutes - if the infrared electric floor was mounted under linoleum or parquet. What is it connected with? The reason for the long warm-up will be the density of the material from which the flooring is made.
from 60 minutes to 3 hours - such indicators will be if you put a warm floor under the tile (directly into the tile adhesive). It can be either a heating mat or a thin heating cable.Why? After the first turn on, the warm floor will first heat the tile adhesive, then the tile, and only then heat the air. This time is calculated on the condition that the cable with a power of at least 150 W / m2 (the Ukrainian market has a huge selection of manufacturers of these electric floors). There are also high power electric floors (more than 150W/m2). So how much does a warm floor under a tile heat up when you turn it on for the first time? Answer: 1 to 3 hours.
from 3 hours to 12-15 hours - such indicators are the norm for a cable in a coupler. Why? According to the recommendations of manufacturers of underfloor heating, a screed of 3 to 5 cm should be poured. To warm up concrete of this thickness, when the underfloor heating is first turned on, in some cases more than 15 hours. Of the minuses: slowly heats up and slowly cools down.