Installation of a warm floor involves the subsequent long-term and uninterrupted operation of the heating system. In a city apartment, a private house or a country house, a water-heated floor is equally effective and convenient. Such a heating system can be equipped in almost any residential area, but the effectiveness of its use depends on the compliance of the technical characteristics of the equipment with the design features of the room. Properly calculated and installed heating circuits, expertly performed pressure testing of the underfloor heating system will allow homeowners to forget about the hassle of maintaining heating devices for a long time.
However, the idyll cannot continue indefinitely — any equipment is not eternal and eventually needs to be repaired. Underfloor heating is a complex complex of a wide variety of equipment, the failure of one of the elements of which can lead to the failure of the entire heating system.
In some cases, for example, in case of problems with the throughput or tightness of the floor water heating pipeline, the preservation of housing has to be drained from the heating circuit.
Let us consider in more detail in which cases it is necessary to drain the liquid from the underfloor heating system, and how this is done.
The main reasons for draining water from the underfloor heating system
There can be quite a few reasons why it becomes necessary to drain the water from the pipeline of the heating system yourself — from the upcoming long absence of residents in the house to replacing the water in the system with antifreeze. In order to do everything right, and not damage the heating system, let’s take a closer look at how to drain water from the warm floor on your own.
A common reason for the need to drain the coolant is the conservation of the heating system for the winter when used in a normal water circuit. This event, before the onset of cold weather, is mainly carried out in summer cottages and country houses that are not used in winter. To simplify and speed up the draining process, special equipment is used.
Important! In housing for seasonal use, failure to drain the water from the underfloor heating circuit before the onset of frost is fraught with defrosting of the system, therefore, the use of antifreezes as a coolant is undoubtedly preferable — in addition to resistance to low temperatures, these liquids are less subject to wear pump parts.
Another equally important measure in the operation of underfloor heating is preventive maintenance on the heating system. Boiler water has a lot of impurities that, when heated, precipitate or form layers on the walls of the pipeline. Due to the decrease in the internal clearance of the heat conductors, the circulation of the coolant in the system is disturbed, and heat transfer is reduced. For this reason, when using water, the coolant must be drained once or twice a year.
A water circuit filled with antifreeze does not suffer from such a problem. The replacement of the coolant in this case is carried out every 3–5 years — provided that the boiler is operated without overheating (for warm floors, the maximum allowable temperature threshold for heating the coolant is 45–550FROM).
Another reason for the need to drain the coolant may be the loss of its physical properties by the liquid. The change in the characteristics of antifreeze occurs after overheating — the solution begins to foam, filling certain sections of the heat pipes with foam, which disrupts the circulation of the coolant in the system and reduces heat transfer.
Failure to comply with the installation technology of a warm floor, the use of materials that are not intended for contact with chemicals, causes the occurrence of corrosive processes in the heating system, as a result of which the circulation of the coolant is also disturbed, and water circuit leaks occur.
Naturally, you will have to drain the water from the underfloor heating pipeline when replacing it with antifreeze — modernization.
These are the main reasons for the need to empty the underfloor heating system and, regardless of the basis, the water must be drained in accordance with all the rules, with the implementation of safety precautions and compliance with the technological sequence of the constituent operations.
Procedure for draining water from the system
Underfloor heating is a closed system, so you need to take care of the drain taps even at the installation stage. The number of valves must match the number of water circuits.
Underfloor heating is actually a long hose laid in the floor. Laying method — the configuration of the contours may be different, but the principle of operation of the water circuit is the same — the coolant gives off heat to the surrounding space by heating the floor surface.
Before starting the operation to drain the coolant, the heating system is turned off, after which the time required for the complete cooling of all its elements is waited.
Given the fact that the water circuit is connected to the main pipeline, and the connection point is located above the floor level, the water is drained forcibly using an air compressor.
Note: the power of a household vacuum cleaner is not enough to empty the underfloor heating system.
Important! To purge the water circuit, a compressor with a working pressure of up to 5 bar is used — the use of a more powerful unit is fraught with the destruction of heat pipes.
Drainage is carried out through a return line equipped with a drain valve, and the compressor is connected to the manifold on the inlet pipe, so the check valve may create some interference when blowing the pipe. After connecting to the collector, the compressor for displacing the coolant from the circuit is turned on, and the air supply pressure is gradually increased — to a value after which the liquid began to flow out at the outlet. It should be remembered that the volume of water in each of the underfloor heating circuits is insignificant, therefore, an ordinary bucket with a volume of 8–10 liters is sufficient to receive it.
The compressor should work until air begins to flow continuously from the pipe following the water.
On a note: if you don’t have a compressor handy, there is another way to free the system from water and avoid defrosting the heating system. A hose of suitable diameter 1 m long with a funnel at the end is tightly put on the inlet of the heat pipe. The end with the funnel is raised higher and gradually poured into it a liquid for washing car windows — “anti-freeze” (it is better to use a brightly colored one). As the water is forced out of the return pipe, and then the technical fluid is a long, but effective process.
Technical subtleties and nuances
In preparation for draining, it is necessary to study the collector device in order to find and mark on the supply and return the location of the valves marked as follows:
- serving — red;
- reverse flow — blue.
Having confused the flow with the return, the drain system will not work — the check valve will block the pipeline.
If there is no receiving container, then you can connect the drain hose to the return valve and stretch it to the nearest sewerage intake — a toilet, sink or drain.
Having finished draining the water from one circuit, all the others are emptied in the same way. During the draining of some section of the system, the valves of the remaining circuits must be closed, and at the end of each stage, the taps of the empty pipelines must also be closed.
To fully empty the circuits, the purge procedure can be repeated after an hour — when moisture drains from the walls of the heat pipes and accumulates in some area.
Periodic draining of water from the underfloor heating system is necessary. The frequency of this operation depends on the intensity of use of the heating system and the quality of the water. In regions with hard water, which also contains a lot of suspended impurities, it is necessary to drain the water from the heating circuit at least once a year.
Replacing the water in the heating pipeline does not require financial costs (except for the possible payment for renting a compressor), therefore it is better to perform this manipulation regularly, thereby extending the time for trouble-free operation of the water circuits.
When using antifreezes, the procedure for draining the coolant is carried out much less frequently — once every 3–5 years, but with increased safety measures — ethylene glycol, used for the manufacture of non-freezing liquids, and its vapors are toxic substances that require the use of personal protective equipment (overalls, gloves, goggles, ventilation) and room ventilation.