How to Use Underfloor Heating: A Guide to the Rules of Operating Heating Systems

Introduction: How to Use Underfloor Heating

Warm floors in rooms are a great way of local or main heating. However, the system will serve properly if it is used correctly. This article is about how to use warm floors. You will learn the nuances of servicing the structure, get answers to questions about the technical side of the miracle invention for heating.

What types of heated floors are there?

In order to discuss the operating rules, it is important to decide on  the type of heated floor .

Groups of structures:

• Infrared:  film , strip and rod heated floors .
• Water heated floors .
• Electrical: cable, film, matte.

The principle of operation of any type of heated floor is the conversion of electrical impulses into heat. In the case of a water system, the conductor is liquid. In infrared structures, carbon strips become heating elements. In cable and matte ones, electric cables.

Construction of a warm floor

To understand how to use a warm floor correctly, you should study the design of the main types of systems. Let’s analyze the “stuffing” of water, cable and infrared heating. Let’s look at photo examples.

Water floor

The most complex design is the warm liquid floor.

Main elements of the system:

• A pump is a device that carries out forced circulation of liquid in pipes. As a result of its operation, optimal temperature parameters are maintained in the system. Centrifugal models with the ability to change the operating mode are suitable for a water floor. Such models allow you to vary the speed of liquid movement along the system circuit.
• A boiler is a device responsible for heating the coolant in pipes. This element is included in a system cut off from central heating.
• The collector is a unit used to distribute liquid along the contours of the underfloor heating system. It is responsible for the uniform circulation of the coolant and its return to the boiler for reheating.
• A thermostat is a device responsible for the heating indicators of the coolant in the system. The device helps to reduce energy costs and optimize the process of operating a heated floor.
• Pipe insulation is a circuit protection system that prevents heat loss and condensation formation.

If the liquid floor system is powered by a boiler, it is important to choose the right model of equipment. Types of devices: gas, electric, fuel-fired, combined. The first two options are the most common.

The water system is compatible with almost all types of finishing coatings. The most common design option is  finishing the floor with tiles .

Infrared floor

Infrared floor  is a polymer base with conductive strips. Film and tape structures are most common. They work due to a heating circuit made of silver and copper elements. These metals are excellent heat conductors.

The rod infrared floor is made in the form of mats with heating elements. The operating principle is similar to the other two types of warm covering.

You can safely lay linoleum, tiles, parquet, laminate or cork on the infrared system. Such warm floors are compatible with almost all finishing options.

How to properly start a warm water floor

To see how the heated floor should work correctly, it is important to prepare the system. We tell you how to do this.

Filling the pipeline with coolant

In order for the water floor to heat properly, it is necessary to organize the supply of the heat carrier. The method of starting depends on the type of system. If tap water is used as the heat carrier, a special tap should be installed. However, special purified liquids are used more often. They are released into the pipes through a tip with a shut-off valve. It can be found in the supply part of the manifold. Automatic and manual pressure testing equipment also takes part in this process. Such devices simplify the supply of the working medium.

Equipment startup

The main task at the start-up stage is to ensure the operating conditions of the heated floor. Namely, to bring it to the desired temperature mode. This is not done in one day, so be prepared to change the settings periodically.

First, set the temperature to 20-25 °C. Then increase the degrees by 5 divisions every day if antifreeze is used as a coolant. Or by 10 degrees if water is used.

The rate of temperature increase depends on the area of ​​heating. For example, to maintain heat in a small room, more “modest” indicators will be enough. Therefore, you will achieve the desired temperature faster. However, do not force the events – as a result of accelerated heating, the screed may crack.

Test run of the water floor system

Checking the underfloor heating for “professional suitability” is a mandatory step. If something goes wrong, it will be easier to correct the shortcomings. However, the check must be carried out before pouring the top layer of concrete screed.

Testing options:

• Air pressure testing.
• Bringing the system to operating temperatures, monitoring for 2-5 days.
• Test on cold coolant under excess pressure conditions.

The third option is considered the least desirable. The absence of a concrete screed and excessive pressure can cause the pipes to fly out of the circuit. Therefore, if you are for this method, use strong fasteners to fix the system. Or fill the pipe sections with small portions of cement mortar. Wait until the composition “sets” and proceed to testing.

The second testing option is the longest. This will be a problem if the room is residential and you want to finish the floor installation as quickly as possible. Therefore, many people prefer to do pressure testing. However, the choice depends on the preferences of the room owners and the type of pipes in the circuits. The table describes the nuances of all testing methods.

Test method	Type of pipes	Technology
Output to operating temperatures	All kinds	Start the system at 20 °C. Gradually increase the indicators (by 5-10 °C per day) to 50 °C. If everything worked out, leave the structure for 2-3 days for observation. Pay attention to the pipes themselves, joints. In case of leakage or components of the circuit, turn off the warm floor, drain the liquid, fix the problem. Then fill the coolant again and test the system. If everything is OK, cool the liquid in the pipes and proceed to pouring the screed
Overpressure test	PERT or PEX products	Fill the system with coolant, create a pressure 2-2.5 times higher than the working pressure. Wait 22-24 hours. If the pressure drops by no more than 1.5 Bar, then there are no leaks in the structure. And you can start installing the screed
Air pressure testing	All types except cross-linked polyethylene pipes	This method is suitable if you cannot or do not want to fill the coolant before installing the screed. The technology will be similar to the previous method. That is, you need to create a pressure in the system 2-3 times higher than the working pressure. If there are gaps in the circuit, a characteristic hissing sound will be heard

The working pressure should be selected based on the pipe material. For example, the optimal value for elements made of metal-plastic or cross-linked polyethylene is 6 Bar.

The most “capricious” material in terms of testing is cross-linked polyethylene. Pipes made of it should be tested under a working pressure of 6 Bar exclusively on a cold coolant. And the procedure will have to be done at least 3 times. And only then can pressure testing be carried out.

Algorithm:

• Increase the working pressure in the system to 6 Bar.
• Wait until the indicator drops, and after 30 minutes, raise the pressure again.
• Repeat the procedure 3-4 times.
• Increase the pressure to the test pressure (2-3 times higher than the working pressure), wait 24 hours.

If the pressure has dropped by less than 1.5 Bar in 24 hours, you can start installing the screed. If the readings have dropped significantly, look for signs of leaks.

Draining the coolant from the circuits

The “correct” warm water floor does not have a tap for draining the liquid. A compressor will help.

Drainage process technology:

• Connect the compressor to the supply manifold.
• Remove the air bleeder from the fluid fill valve located on the manifold.
• Screw the adapter into place of the air vent and connect it to the compressor outlet.
• Attach the hose to the drain hole on the return manifold.
• Lead the hose into the sewer or coolant container.
• Check that the shut-off valves on the desired loop of the pipeline (from where the liquid will be drained) are open.
• Turn on the compressor.

After connecting the compressor, the coolant under pressure will start to leave the circuit. The signal for the end of the process is the appearance of airborne suspension. When this happens, turn off the compressor, close the loop valves, open them on the next segment of the circuit. Repeat the procedure for draining the liquid. And so on until the end of the circuit.

It is enough to change the antifreeze heat carrier once every 3-5 years. And water – once a year. If you neglect the rules, the operation of the heated floor will be at risk. The outlived heat carrier will no longer fully perform its functions.

Temperature of heated floors

The rules for operating heated floors do not regulate exact temperature readings. However, there are recommendations:

• The optimal surface temperature of a heated floor in a living space is 28 °C.
• The floor temperature in rooms with low traffic (bathroom, loggia or balcony, terrace) and in rooms where the warm flooring serves as the main source of heating is 32 °C.
• The optimal air temperature for a living space is 21-26 °C. The most comfortable parameters are 21-22 °C.

If you greatly exceed the recommended values, it will be uncomfortable to be in the rooms. Therefore, it is better not to deviate more than 1-3 degrees. Then the underfloor heating system will last longer.

Adjusting the temperature of heated floors

The method of temperature regulation of a heated floor depends on the type of system.

Setting options:

• Adjusting the coolant temperature . A method for a water-heated floor that operates from a boiler. However, in this case, you will have to be content with low temperatures. In addition, separate heat generators are rare.
• Temperature control using mixing units and manifolds . You can change the settings both for individual segments and for the entire circuit.

To regulate the heating of cable, cable-matt and film floors, a temperature controller is required. However, there are also self-regulating designs. In such systems, cables change the heating power depending on environmental conditions.

Sensors are used to record the temperature. In water systems, they are usually mounted on collectors. In electric variations, they are mounted in the floor structure. If you choose a system with automatic control, you can install air temperature sensors. They are placed directly in the heated room.

Is underfloor heating dangerous?

Many are afraid to integrate a heating system due to concerns about harmful radiation. If you know how a heated floor works correctly, there will be no danger. It is logical to expect troubles only from the household side. For example, leaks may occur in the water system. Therefore, it is better to make insulation and test the structure several times before laying the finishing material.

And one more thing – any electric heated floor is fire hazardous if installed incorrectly. Therefore, be sure to follow all installation stages. Or entrust the task to specialists.

While you are choosing heating system options, check out  the technology of self-leveling floors . Creative, effective finishing will definitely inspire you to design feats.