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Buying a water heater is not everything. It still needs to be installed, and then connected. And connect to both water and electricity. How to install a water heater depends on its type: instantaneous or storage. Depending on the size and shape, the installation site is selected. The requirements for the power supply line depend on the power, and the connection scheme to the water supply depends on the internal structure of the water heater.
Types of electric water heaters
There are two large groups: flow and storage. Instantaneous water heaters heat the water that passes through them. In this regard, they are relatively small in size, but very high power – up to 24 kW, but this is the maximum. For washing dishes and taking a shower, a power of 4-6 kW is enough, for taking a bath – 10-12 kW. So, to connect such equipment, a dedicated power line with an RCD is required.
Storage water heaters are also called “boilers”, they have a reservoir and a small, compared with flowing, power – from 0,8 kW to 4 kW. However, a separate power line is also desirable for them. Boiler sizes depend on the volume of water contained in the tank. Their shape is cylindrical, and the cylinder can be located vertically (cheaper option) and horizontally (more expensive).
The place for installing the water heater is chosen mainly depending on the existing connection conditions. Most often, this is either a bathroom or a kitchen: water is supplied to both rooms. Secondly, the place is chosen for aesthetic reasons: so that the equipment is not very “striking” to the eye. From this point of view, a toilet or a bathroom is usually chosen. If space is available, this is the best choice.
How to install a boiler ( storage type water heater)
Let’s start with mounting on the wall, because that’s where it is usually attached. Empty boilers have a solid weight, and even they contain up to 150 liters of water. Therefore, strict requirements are imposed on the mount: they must withstand twice the weight, equal to twice the capacity. That is, if you have a boiler of 80 liters, the fasteners must withstand 160 kg. In this regard, it is mounted only on bases with good bearing capacity on anchors with hooks.
There is a mounting plate on the back wall of the water heater at the top (sometimes there are two of them – at the top and at the bottom). It has slots through which hooks are threaded. Thus, the boiler is hung on the wall. There are two different ways to mark where to drive fasteners:
- If there are assistants and the space allows you to move relatively freely, you can lean the boiler in the right place against the wall, and then circle the slots.
- Measure the distance at which the bar is from the top of the water heater, also measure the distance between the centers of the mounting holes. Set aside all these parameters on the wall by finding the necessary points.
One caveat: if you are going to hang the water heater under the ceiling, it is necessary that there is a gap of at least 5 cm from its top to the ceiling. This is necessary so that it can be lifted by putting it on hooks. Otherwise, hanging the boiler will not work.
How to connect the boiler to the water supply
We will proceed from the fact that there is already a cold water supply point, as well as a hot water distribution comb. A little about how to connect the boiler outlets to the hot and cold water pipeline. It is more convenient to use flexible hoses, but not those that are just braided rubber, but flexible ones made of corrugated stainless steel. They also have different lengths, they have union nuts with gaskets at the ends, but their service life and reliability are many times higher. If the boiler hangs over the bathroom and all the connections are in the same place, then even if the hoses burst, nothing threatens you: the water will end up in the bathroom. If not, you can flood the neighbors.
Another option is to use plastic (polypropylene or metal-plastic) pipes. This option is used if hot water is simultaneously distributed to distribution points. Otherwise, it is more convenient to use flexible connectors. Only when using pipes, please note that special pipes are placed on hot water, which are usually marked in red, on pipes for cold water it may not be at all, or it has a blue / blue color.
Now directly about the scheme of connecting the boiler to the water supply. Although modern water heaters are often equipped with automatics, periodically, when heated, a sharp pressure surge occurs, which can lead to a violation of the tightness of the container. To avoid surges, a safety valve is installed on the cold water inlet. When the threshold value is exceeded, a tap opens in it and some part of the water is bled off, equalizing the pressure. Therefore, when installing the faucet, make sure that the drain outlet (small socket) is directed downwards. If you want your boiler to work for a long time, put this valve in place.
It is convenient if it also has a second function – it also works as a check valve, blocking the outflow of water in the absence of pressure in the system.
If you look at the photo, there is an arrow on the body that shows the direction of water movement. If there is such an arrow, the device also works as a check valve, preventing water from pouring out. If there is no arrow, you will also have to install a check valve (above the safety valve).
For information on what functions the safety valve performs, and how best to install it if it is not located above the bath, see the video.
Another obligatory detail of the scheme is shut-off valves. They are usually placed on a branch from the riser of hot and cold water. These faucets are required. Sometimes they are also placed in front of the security group, but they are no longer mandatory, but serve only for more convenient repairs.
The safety group is a coarse filter and a pressure reducer. If these devices are not at the entrance to the house or apartment, it is very desirable to install them: they extend the life of the water heater.
See the video for an explanation of the boiler connection diagram, and typical errors in connecting to the water supply are also discussed here.
Connecting the boiler to electricity
All manufacturers of water heaters recommend turning on the boilers to electricity to a separate line from the electrical panel, on which a double automatic machine and an RCD are installed. Please note that the automatic machine is necessarily double – that is, one that breaks both phase and zero at the same time. A ground connection is also required. These measures provide security, so they should not be neglected.
Instead of a bunch of RCD + automatic machine, you can put a difavtmat. It will also monitor both leakage current and short circuit, but is made in the same package. A 16 A automatic machine is enough for a medium power boiler, and an RCD leakage current of 10 mA. The cross section of the copper wire (mono-wire) is enough 2,5 mm.
How to install a tankless water heater
As already mentioned, the instantaneous water heater has smaller dimensions, therefore it is easier to find a place for it. It can be hung next to the wall, or you can hide it in a cabinet. Its dimensions are usually 15*20cm*7cm or so. In general, they are small. Weight – from the strength of 3-4 kg, so that the requirements for fasteners are minimal. Usually it is either hung on two dowels of small diameter screwed into the wall, or it has a mounting plate that is screwed to the wall, and the water heater is already hung on it. We figured out how to install a flow-type water heater, now about the connection.
Connecting the instantaneous water heater to the water supply
From this side, everything is simple. But the disadvantage is that it can only supply water to one point at a time. Depending on the installation location, either a shower head with a flexible hose or a gander for washing dishes is placed at the outlet of warm water. It is possible to put both the “gander” and the watering can through the tee (as in the picture on the far right).
In order to be able to remove the water heater if necessary and not shut off the water in the entire apartment or house, ball valves are installed at the inlet and outlet. They are required equipment. The connection from the nozzles to the tie-in point in the cold water supply line is carried out in the same way as when connecting the boiler: with corrugated stainless steel hoses or plastic pipes. Hot water to the point, if necessary, is carried by a flexible hose: in principle, there are no temperatures too high here, so it must withstand.
Another feature of instantaneous water heaters is that they can normally only heat a certain amount of water. With an increase in flow or too low an inlet temperature, they do not cope with the task. Therefore, most often such a water heater is used as a temporary one – in the country or when the hot water supply is turned off for prevention (for the summer).
It is not difficult to solve the problem with an excessive amount of water (when the pressure rises above the norm): either put a reducer at the inlet or a flow restrictor. The reducer is a more serious device and it is recommended to install it at the entrance to the apartment, and the flow restrictor is a small cylinder with a valve. It is screwed onto the cold water inlet. An example of how to install a flow type water heater and where to wind the flow restrictor is in the video.
Electrical connection
With the electrical part of the connection, everything is the same as with the boiler: a dedicated line, RCD + automatic. Others are only ratings and wire cross-section. Rated at power up to 5 kW – 25 A, up to 7 kW – 32 A, from 7 to 9 kW – 40 A. The cross section of the copper wire is 4-6 mm (monofilament).