How To Replace Heating In An Apartment With Your Own Hands

2023 Author: Douglas Hoggarth | [email protected]. Last modified: 2023-05-24 11:23

• Installation of radiators

  • How to hang a radiator
  • What is a radiator piping kit for?
  • How to install taps on a radiator?

• Installation of the supply pipeline

  • Which heating scheme to choose?
  • What pipes to use for heating installation?
  • How to choose the diameter of polymer pipes for heating?
  • How to lay heating pipes?
  • How is a polypropylene pipeline assembled?
• Checking the operation of the heating system

In most Soviet-built houses, heating pipes and radiators have not changed for several decades. During this time, the system is pretty much clogged with rust and other deposits, its efficiency and reliability are steadily falling from year to year. There is no need to talk about any aesthetics of open painted pipes. Therefore, many of our compatriots, starting more or less major repairs, are forced to make a complete replacement or serious modernization of heating, especially since new progressive technologies and materials have become available. Very often, certain changes have to be made to the heating system of apartments in new buildings.

New building. Walls need to be sheathed with plasterboard and insulated. Reinforced-plastic pipes are stained with mortar and have microdamages. Connecting from the floor in the future will significantly complicate the installation of parquet boards. All indications for reworking the heating are evident.

Replacing heating is a very responsible and time-consuming business, it is not surprising that many people prefer to hire professionals. But there are those who are ready to study the technology in detail, purchase or rent a special tool and do everything on their own. One way or another, but the order of actions will be the same:

1. We coordinate the work with the housing office (shutting down the system, discharging water).
2. We agree with our neighbors to replace the risers above and below the floors.
3. We dismantle the old heating.
4. We pack and hang radiators.
5. We cut the threads on the risers.
6. We assemble the pipeline and connect the heating devices.
7. We are testing the system.

Next, we will consider the most common option for modernizing the heating system using polypropylene pipes. Let's start with point # 4.

Installation of radiators

How to hang a radiator

Regardless of the type of radiators you choose, you must first prepare a place for their installation. In most cases, radiators are installed under the windows to ensure proper air convection. During the overhaul of an apartment, the outer walls are often insulated, they are overgrown with a layer of heat insulator and, accordingly, metal frames. There are two problems. First, you need to determine exactly at what distance the radiator will be located from the supporting base. Secondly, it is quite difficult to fix the radiator well on drywall, especially a heavy cast iron one. Therefore, the wall on which the radiator will be hung must be sheathed with a frame in advance. If the walls are leveled or plastered from scratch, at least beacons should be installed.

In the case of the frame, at the places where the fasteners are installed, it is necessary to make inserts of plywood or OSB with a thickness of 25 mm, which go into the inside of the UD profile and rest on the floor with their lower part. For each heater, you need 2 or 3, depending on whether 4 or 6 brackets will be used.

When the base is ready, you can mark the location of the fasteners. To do this, a radiator on temporary stands with the help of a level is installed in the design position, usually in the center of the opening, 100-150 mm from the finished floor, at least 100 mm from the window sill. The radiator is removed, holes for the brackets are made with a perforator, after which they are screwed in so that a gap of 30-40 mm remains between the rear surface of the heater and the wall.

A gap of 4 centimeters is left between the wall and the radiator.

For a cast iron radiator with more than 10 sections, we recommend using at least 6 fasteners. In other cases, four brackets are sufficient.

What is a radiator piping kit for?

Typically, radiators are sold with four open entrances - two on each side. The fact is that there are several types of connecting heating devices: one-sided, cross, one-pipe, bottom. Depending on this, some entrances are closed with blind plugs, and some with ½ or ¾ inch threaded bores. Installation of plugs and valves and fittings is called "packing" of threaded connections. The procedure for piping a radiator is actually one of the most critical when installing heating, it is on threaded connections that leaks most often appear.

An example of a left one-way connection. A small cast iron radiator is hung on four brackets.

The most effective for heating an apartment is one-way connection of radiators, it is also the most common. On the right or left of the radiator, the supply enters from above, and the return outlet will be on the bottom along the same side. On the opposite side from above, a Mayevsky valve will be installed to release air, the lower inlet is closed with a plug-plug.

Above there is a Mayevsky valve for air discharge, at the bottom there is a plug.

To prepare each heater for installation, you need to purchase a set of four plugs - three through, one deaf. Plugs come with a right-hand or left-hand thread, so you need to choose them based on what thread is in the inputs of the extreme sections of the radiator. The lead-through threads of the plugs can be ½”or ¾”. If the supply is carried out by the twentieth pipe, then we take plugs with a passage of half an inch, if with the 25th pipe (vertical one-pipe system, the radiator is part of the riser), then the plug should be only ¾.

Attention! The plugs are screwed into the radiator with a noticeable effort, without the use of any winding, since they have sealing gaskets. Even on new heating devices, the area to which the cork gasket is adjacent should be cleaned with a knife blade from paint deposits, scale, and rust.

The "regular" cast-iron radiator is packed with new plugs, since the connection diagram has changed.

How to install taps on a radiator?

Now, shut-off and control valves can be installed in the through plugs. These can be “full bore” ball valves for radiators or valves with manual regulation of the coolant flow, including thermostatic heads with automatic regulation.

There are several typical designs of faucets for heating, but the most practical are those with American union nuts. American taps allow you to quickly shut off the coolant flow, untwist the threaded connection and remove any radiator without stopping the system. This is especially important, given the fact that heating devices are often hung and connected almost to the rough wall, after which it is still necessary to close up the grooves, sew / plaster the walls, putty the surfaces, and glue the wallpaper. The most important thing is that the American woman can be used many times, regardless of whether it has a rubber or parasite gasket, or the sealing is carried out only due to the conical metal parts.

Depending on where the supply pipes come from to the radiator, from the wall or from the slopes of the niche, straight or corner taps with union nuts are used.

The radiator is located in a niche, so the connection is made by a direct American. The valve is a metal ball valve, the threaded coupling with a transition to plastic is "flush" with a slope.

To screw the American into the radiator cap, you must use a special wrench, which is inserted into the inside of the pipe with a union nut. Its sectional shape can be quite varied. The easiest way, if you need a hexagon, you just need to choose its size. It is somewhat more difficult when inside the American woman we have two protrusions, then we have to select a suitable profile for a reliable hook. Sometimes for these purposes, jaws are used with pliers or an adjustable wrench, but many craftsmen prefer to make an L-shaped square wrench, the ends of which go slightly to a cone, which allows working with American women from different manufacturers.

The connection between the American pipe and the passage plug must be sealed with a winding. Most plumbers use imported flax strands for this in combination with UNIPAK-type investment paste. FUM tape is suitable only for high-quality "pipe" threads that have a profile without sharp corners and a special notch that prevents the sealing material from rolling.

We recommend that you first check the compatibility of the threads of the two parts, for this we connect them without tow. Depending on how tightly the connection is assembled, it becomes clear how much tow is needed. Too large a layer of winding can lead to deformations, the formation of cracks on the body of thin-walled parts. Too little layer can cause leakage.

The winding is carried out only in the direction opposite to the direction of the thread on the branch pipe. The separated flax fibers are collected in a thin rope, which is wound tightly, starting from the outer edge of the thread. Each new loop must press the previous one, preventing it from scrolling. When the entire depth of the thread is filled with the winding, it is lubricated with paste and the part is screwed into place.

The pipes of the American women, without reeling, entered the passage plugs very tightly, so we seal the connections with FUM tape.

If not plastic, but metal ball valves are used in the heating system, then threaded couplings should also be screwed onto them with the use of winding to switch to polypropylene.

The Mayevsky crane from the strapping kit has a rubber gasket, so there is no need to rewind it.

The wrapped radiator is hung in its place - you can start soldering the pipes.

Installation of the supply pipeline

Which heating scheme to choose?

There are two main heating systems - one-pipe and two-pipe. When replacing pipes and radiators in an apartment, you don't have to choose from them, they just largely determine some differences in the technological chains. We strongly recommend not to make drastic changes to the existing heating scheme, so that there are no problems with the heat supplier and neighbors.

The one-pipe system is most widespread in typical Soviet-style apartments. Its idea is that hot water flows from top to bottom along vertical risers, from which the radiators are supplied with tees, crosses or "burst". Usually there are several such risers in an apartment, one for each room, including a heated towel rail line in the bathroom. The main disadvantage of the "vertical" system (as it is sometimes also called) is the difficulty of adjusting the temperature of heating devices, as well as the fact that the radiators on the lower floors are noticeably colder than on the upper ones.

The two-pipe system is used in private houses and cottages, as well as in apartments in new buildings. With such a system, two pipes are used, through one of which hot water is supplied, and the other is intended to remove the cooled coolant - "return". If with a one-pipe system, the heating devices are connected in series, then with a two-pipe system - in parallel. This makes it possible to set a certain temperature of the radiators using various flow regulators installed on the flow line.

New building. An installation cabinet for heating a separate apartment is located in the common hallway. The heating system is two-pipe horizontal. During one heating season, the metal couplings had time to rust, there are leaks at the connections. The entire node needs to be "enumerated".

What pipes to use for heating installation?

The choice of pipes for creating a heating system must necessarily be made taking into account the specific operating conditions. Here it is necessary to take into account the chemical composition of the coolant, its temperature and pressure; hidden or open mounting method; compatibility of pipe materials with other elements of the system. The market offers heating pipes from a variety of materials, for all kinds of conditions and for every wallet.

Perhaps the best option for installing an apartment heating system will be polypropylene (PP) pipes. They have proven themselves well and have become very popular both in Russia and in Europe. Their main advantages are:

• corrosion and chemical resistance;
• low thermal conductivity;
• no impact on the organic composition of water;
• smoothness of the inner walls;
• low cost;
• simplicity of the connection process.

There are several variations of polypropylene pipes, each of which has its own purpose and, accordingly, special properties. In any case, when choosing, you should pay attention to the PN marking. It indicates the nominal pressure that the pipes must withstand. For heating, only reinforced (composite) pipes PN25 must be used. The reinforcing layer eliminates two disadvantages of polymer pipes: a high coefficient of linear thermal expansion, as well as the permeability of plastic walls to oxygen, which can cause corrosion of metal fittings and heating devices, the appearance of air locks. Reinforcement is performed by placing it in the body of the pipe, between layers of polymer, aluminum foil, solid or perforated. Also, plastic heating pipes are reinforced with fiberglass,which is mixed with polypropylene and applied in a separate layer in the middle of the pipe. This layer is colored, it is clearly visible on the cut.

To connect a reinforced pipe with fittings, aluminum foil located close to the surface must be removed with a special manual chuck. This process takes a lot of time, attention and energy. We recommend paying attention to pipes in which the foil is located closer to the middle, which makes it possible to significantly simplify the task - they do not need to be cleaned. Fiberglass-lined pipes also do not require stripping.

How to choose the diameter of polymer pipes for heating?

The diameter of heating pipes is determined based on complex hydrodynamic calculations. In these calculations, the pipeline diagram, the characteristics of the radiators, the characteristics of the coolant, the working pressure and other parameters are taken into account. One of the main tasks in the design of heating is to select pipes of the smallest allowable diameter, which will ensure its correct functioning with the least amount of coolant. A slightly overestimated diameter in a centralized heating system will not harm, but only affect the cost of the pipeline. But too thin a pipe significantly reduces the pressure of the coolant with all the ensuing consequences.

Fortunately, we do not need to master complex formulas, practice shows that pipes with an outer diameter of 32, 25 and 20 mm are used for distributing apartment heating. So for risers of a vertical one-pipe system, a 32 or 25 pipe is used, for supplying to radiators - a pipe with a diameter of 20 mm.

The situation is a little more complicated with a two-pipe horizontal system. Here you need to take into account the length of the whole sections and the number of connected heating devices. So if a section of the pipeline feeds more than 8 radiators, or when its length exceeds 30 meters, it is necessary to use a 32 mm pipe. A pipe with a diameter of 25 mm is used if there are less than eight radiators after this section. Individual heating devices are connected to the system by means of a pipe with a diameter of 20 mm, provided that these sections are no longer than 10 meters.

As the water intake is realized, it makes sense to reduce the diameter of the supply pipeline by switching to a thinner pipe.

Two-pipe horizontal system. After the outlets for heating the first rooms, the pipe was narrowed from 32nd to 25th diameter. Each radiator is powered through a reducing tee (32x32x20; 25x25x20) - a pipe with a diameter of 20 mm.

How to lay heating pipes?

If earlier outdoor heating was considered the norm, now most developers prefer aesthetically grounded hidden installation of pipes, so it is simply impossible to imagine plumbing work without cutting grooves in the floor or walls. Obviously, with a horizontal two-pipe system, the best option would be to lay pipes in the floor structure, while we still recommend connecting radiators from the wall. If the floors in the room are concrete, then you can make a wiring, both before pouring the screeds, and by cutting grooves in already finished coatings.

It is better to place the supply and return pipes in separate grooves, the distance between which should be about 100-200 mm. This makes installation more convenient, and the pipes heat each other less.

To ensure free thermal expansion, polymer pipes that are in the screed must be insulated with a foamed polyethylene sleeve. For the same reason, we recommend filling the space near the fittings with mineral wool or other soft material.

Do not fasten the pipeline to rigid fasteners; if necessary, use movable supports in the form of plastic clamps or brackets that do not impede the linear expansion of the pipeline. However, fix the pipes very carefully where they exit the wall or radiator niche.

Each groove must have sufficient width and depth for free laying of pipes wrapped with insulation. When expanding linearly, the pipes should not rest against the sides of the groove.

The tracks should be run parallel or perpendicular to the walls, all turns should be done only at right angles. Z, P and L-shaped pipe bends help compensate for thermal expansion. To bypass adjacent pipes, you must use ready-made contours. In frame structures, flexible compensating loops for polypropylene pipes can be used.

Free wide grooves are turned strictly at right angles. The radiator is temporarily suspended on a bare frame. Plywood embedded elements are visible between CD-profiles. Two "tails" made of polypropylene entered the wall, it remains only to solder the terminals for connection.

It is recommended to draw up a detailed diagram of the floor heating installation. In addition, in order not to break through the pipes at the subsequent stages of repair, it is convenient to have at hand photographs of especially difficult, vulnerable areas against the background of a tape measure stretched from the enclosing structures.

Having laid a sheet insulation with a reflective layer along the bottom of the groove, you can direct the thermal radiation into the interior of the room, get the effect of a local warm floor.

A vertical one-pipe system does not have long horizontal sections, since each radiator has its own main line, so new pipes and risers are usually hidden in the wall grooves or under the frame of plasterboard systems. Heating pipes in the outer walls must be insulated.

How is a polypropylene pipeline assembled?

It is most convenient to install heating pipes in the direction from the risers to the already hung and "packed" radiators. Decide in advance where you will make the last soldering. This should be a place with good soldering iron access and long pipe travel, usually between the wall and the radiator.

They cut polymer pipes with special scissors. The size of each straight section of the pipe is measured with a tape measure in accordance with the plan diagram or the configuration of the prepared strobes. Do not forget to take into account that on average about 15 mm of pipe goes into the fitting.

If a pipe reinforced with aluminum is used for heating installation - "stabi", then in most cases its end parts should be pre-cleaned with a special chink. Further work is carried out as with ordinary pipes.

The connection of polypropylene pipes is made by thermal welding using various fittings: elbows, reductions, couplings, tees, crosses, contours … For this, a special hand-held soldering iron with replaceable nozzles is used, which melts plastic pipes and fittings simultaneously.

After the welding machine has completely warmed up (this is controlled by the indicator), the cut-to-size pipe is inserted into the coupling part of the nozzle, in turn, the fitting is put on the mandrel nozzle until it stops. It is very important to maintain a certain melting time. If you heat the plastic too little, the connection will not be reliable enough; if you overexpose the pipe and fitting in the nozzle, then deformations of the working surface of the joint with a "narrowing" of the inner diameter or even blockage of the pipe are possible. Pipes with a diameter of 20 mm melt in about 4-5 seconds, the 25th diameter needs to be heated for 7-8 seconds, the 32nd pipe - about 10-12 seconds. If the air temperature in the room is at around +5 and below, the time for heating the plastic should be increased by 50%.

It is important that the welding machine is set at a suitable temperature recommended by the manufacturer of the polypropylene pipeline, usually around 250-300 ° C.

Attention! We do not recommend soldering pipes and fittings from more than one manufacturer to each other, as they may take different times to melt.

After the surfaces of the plastic parts to be joined have melted, they are removed from the nozzle, and the pipe is quickly inserted into the fitting within 3-4 seconds. It is necessary to securely fix the parts in a predetermined position for 4-6 seconds, while not exerting a noticeable force on the joint. Do not skew the parts to be joined relative to the common axis, do not rotate them relative to each other during welding. Cooling down, the parts are firmly welded together, becoming a single whole. You can continue soldering near a fresh connection after it has completely cooled down.

So that the outlet fittings - knees, tees, crosses after soldering are located in a strictly defined direction, experienced craftsmen try them on cold to the pipe and use a pencil or marker to put risks located along one line. The mark on the pipe is placed at least 15 mm from the edge (this distance will cover the depth of welding), the mark on the fitting is placed near the joint. Further, connecting the two elements, it remains to simply combine the two risks.

In accordance with a predetermined plan on the floor or on the wall, sketch the path of the supply pipe. Even if you have already cut all the grooves, draw all the necessary fittings near them. This will help to calculate the required amount of material, as well as to accurately manufacture some enlarged parts.

The heated surfaces of pipes and fittings must be clean and dry - this is a guarantee of the strength of the connection.

Make sure that there are no foreign particles, residues of molten polypropylene on the heated nozzle. If necessary, wipe the attachment with a clean cloth. If the material regularly sticks to the nozzle, then the non-stick coating has become unusable - it needs to be replaced.

It is not necessary to solder the pipeline strictly one element at a time, moving in a certain direction, moreover, in some places it is simply impossible. Sometimes it is more convenient to make enlarged parts of the pipeline, and then connect them in place.

It is better to assemble the heating together - one works with a soldering iron, the other heats up and connects the pipes to fittings. In some cases, the assistance of a third person may be required to fix the pipe that passes the wall or ceiling.

We advise you to pre-practice soldering polypropylene pipes. Study the instructions for the welding machine and the recommendations of the manufacturer of the piping elements.

To avoid accidental burns, use gloves when welding.

Checking the operation of the heating system

After completing the installation of the heating, it must be checked for leaks. For this, a hydrostatic test of the system is performed under pressure, which should be 1.5 times higher than the nominal one. In this case, it is impossible for it to exceed the maximum permissible for specific heating devices.

The system is filled with water from the bottom up. With a two-pipe horizontal scheme, it is better to start by opening the return line - so the air in the radiators will be pushed upward, from where it is discharged using Mayevsky's taps. Then, using a pressure pump connected to the system, the pressure is raised. A pressure gauge is monitored for a significant drop in pressure, visually check for leaks on threaded and welded joints. The whole check lasts about half an hour, if the gauge needle is in place, then there are no leaks, the pipes can be poured with concrete - the system is assembled with high quality.

Be extremely careful and attentive when installing and replacing heating. Regular leaks and ruptures of pipelines can cause serious destruction and damage, resulting in the need to make expensive repairs in several rooms at once. This stems from high pressure, high temperature of the coolant and … the notorious "human factor". Only a competent choice of materials and strict adherence to the installation technology will ensure the safe and durable functioning of the heating system.