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Do-it-yourself selection, installation and connection of an electric water heater

 


Do-it-yourself selection, installation and connection of an electric water heaterA detailed description of the selection and installation of an electric water heater in the apartment

Disruptions in the supply of hot water to our apartments and houses occur quite often, and in some cities and regions it is simply regular and this causes great inconvenience to many families.

If the house has small children, then the lack of hot water from a small temporary inconvenience turns into a real problem. However, solving this problem is quite simple and not even too expensive by installing an electric water heater.

First, let's decide what principle of action do you need a flow or storage heater. Instantaneous electric water heater is cheaper, much more compact in size and very easy to install. However, one significant drawback often makes its use in apartments unacceptable, it is high power.

And the point here is not even a large consumption of electricity, a flow heater instantly brings the water to the desired temperature, and does not spend electricity for 30-40 minutes to heat a large volume of water as boiler (storage water heater). It’s just that when the instantaneous water heater operates, the load on the electric network is too high, for which it simply is not designed.

electric water heaterPower instantaneous water heaters It varies from 3 to 8 kW, and at 3 kW you can wash your hands maximum, for a shower or bath you will need at least 5 kW. With a power of 5 kW, in single-phase voltage networks, the current strength is approximately 23 A, and if you have old wiringthen an aluminum cable of 2.5 mm2 is laid for which a load of 20 A is already ultimate. Therefore, if you want to install a instantaneous water heater, you will have to pull a separate cable from the switchboard. Plus, you need to look at the cross section of the cable supplying your shield and calculate whether it can withstand the additional load.


Storage water heater power usually does not exceed 2 kW, so it can be connected to a common outlet. According to the design of the storage tank, the heaters are vertical and horizontal, round and flat.

The form does not affect the technical characteristics, choose a heater in accordance with your ideas about the design and the availability of free space for placement. But keep in mind that models with a flat tank will cost significantly more than round ones. The case is most often made of plastic, the inner tank is stainless steel.

Determine the volume, if we are talking about an apartment enough tank from 30 to 50 liters. A 30 liter water heater will be enough to shower and wash a family of three, but if you want to get a hot bath, 30 liters is not enough.

With a tank of 50 liters, this can already be done. Of course, you can choose a water heater for 80, 100 liters, just keep in mind that along with the volume, the time for heating the water will increase, and the temperature will have to be maintained in a larger volume, and, consequently, will increase power consumption.

Thirty liters will be heated for 40-50 minutes, and 50 liters is already 1h 10-1h 20. The optimum power for a thirty-liter heater is 1.5 kW, and for a tank of 50 liters it’s nice to have two plug-in heaters, say, the first with a power of 1.2 kW and the second 0.8 kW. And it is also very important that the heater was equipped with a thermostat, and it was possible to set the desired heating temperature.

So, we bought an electric water heater and install it in a pre-selected place. In an apartment, he is most often located in the toilet over the toilet.All models up to 200 liters are made wall-mounted, the kit comes with a special strip, which we attach to the wall on an anchor or dowel-nails and hang a heater on it.

electric water heaterNow the most interesting thing is to bring water to it. If plastic pipes leave your riser, then there are no problems and you do not need to call the plumber for installation. You need to get a welding machine for plastic pipes with couplings of the desired diameter (most often d20 is enough) and scissors for cutting pipes.

All this can be bought if you plan to use it in the future, but you can rent it in almost any plumbing store. Even if you have never used a pipe welding machine, it will be very easy to understand its operation. It is also necessary to buy plastic pipes of the desired diameter, as a rule, this is ½ inch or 20 mm, which is one and the same.

We measure the distance from the pipes of hot and cold water supply to the connecting pipes located at the bottom of the water heater and according to this we purchase pipes. You will also need two tees of the corresponding diameter, two taps for hot and cold water and two couplings with a union nut for connection to a water heater. And, a little advice, do not take plastic made in China, it is better to give preference to Russian, German or Czech companies.

In the chosen place, with the help of scissors we cut the pipe of cold water supply and weld the tee there. The pipe departs from the tee to the water heater, on it in a place convenient for access, we install a crane for supplying cold water to the water heater and at the end we weld the sleeve with a union nut, with which we connect to the heater inlet pipe.

We tighten with a cap or gas wrench, the connection is threaded, so tape-fum or plumbing thread should be applied to the thread. We do the same with a hot water pipe and attach it to the outlet pipe of the water heater. Plumbing work is completed.

Our electric water heater, so you need to connect it to the electrical network. With some models of electric water heaters, a power cord is included, but if it is missing, we will do it ourselves.

We measure a piece of copper three-core cable with a cross section of at least 1.5 mm2 to the outlet into which the water heater will be turned on and install a plug with grounding at the end. The second is inserted into the terminal box of the water heater and connected, the main thing is to connect the earth wire correctly, usually the terminal block is connected to the case using a yellow-green wire.

Everything is done, and you can test. Turn off the hot water supply from the riser, open the tap on the cold water supply to the water heater and at the outlet of hot water from it. Apply power to the water heater and install temperature controller to the maximum. Wait for the heating time set in the passport, while carefully inspecting the pipe connections for leaks. And if everything is fine, open hot water and use to your pleasure. Now you are not afraid of any shutdowns of hot water.

Mikhail Barsukov

See also at bgv.electricianexp.com:

  • The device of a flowing water heater, principle of operation, circuit, type ...
  • How to choose a storage water heater
  • We independently carry out preventive maintenance of a water heater
  • The method of connecting a water heater and pump with insufficient network power
  • An example of sharing a voltage stabilizer with an optimizer ...

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    Comments:

    # 1 wrote: | [quote]

     
     

    This manual is good for new buildings. But what about houses where there is no grounding? We will not connect the neutral wire to the ground. And such when I was when I was my electrician in the housing office I often saw. It also happens that the "kulibins" are grounded to the heating battery.

     
    Comments:

    # 2 wrote: Igor | [quote]

     
     

    In the absence of grounding (old building), I'm going to put an RCD.For the bathroom, the trip current selected 10mA. any leak to the enclosure or pipes will turn off the power, leaving users alive.

    Down with the Kulibins!

     
    Comments:

    # 3 wrote: | [quote]

     
     

    It is also necessary to buy plastic pipes of the desired diameter, as a rule, this is ½ inch or 20 mm, which is one and the same.

    it's not the same thing! 1/2 "- 15mm, 20mm - 3/4"

     
    Comments:

    # 4 wrote: | [quote]

     
     

    Before connecting to the mains, fill the tank with water.
    Before tightening the union nut, it is necessary to put the gasket on, do not wrap any FUM on the thread ...
    The subject of the check valve is not disclosed ...
    But are there water heaters WITHOUT a thermostat? =)
    With an additional sensor from overheating - it can be.

     
    Comments:

    # 5 wrote: MaksimovM | [quote]

     
     

    I would not recommend using a dowel-nail for mounting the water heater. I know several cases when the dowel nails fell out of the wall under the weight of the tank. If so logically, how can two dowel-nails withstand a load of 50, 80, and even more so a 100 liter water heater? No way. A water heater without water under its own weight already bends these nails, and when the water heater is filled with water, it will literally hang in the balance.

    At the expense of the process of connecting the pipelines to the water heater, it seems to me more logical to indicate that there will be no problems and no need to call the plumbing if the pipelines are made of metal-plastic pipes, since it is quite simple to install the pipeline from metal-plastic pipes. Moreover, all work can be performed without the use of a specialized tool, using tools that almost everyone has: wrenches for screwing fittings, hacksaws for cutting pipes and a suitable element to align the edges of the cut pipe (similar to a calibrator). While the installation of plastic pipes requires the presence of a soldering iron for pipes, which in most cases is not on the farm, since it is not practical for an ordinary person to purchase this device for one-time work.

    As for the wire required to connect the water heater to the electric network, in this case it all depends on the amount of power consumed by this appliance. Therefore, if the power of the water heater is 1 or 1.5 kW, then you can choose a wire with a smaller cross section. By the way, the cord that comes with the water heater in most cases has a cross section of 0.75 or 1 square. mm I would recommend before connecting the water heater to the electrical network to make sure that the cord supplied in the kit can withstand the load of this appliance.

    You can also add that the electric water heater can be connected to the electric network in another way - from a separately installed box with a two-phase circuit breaker or a difavtomat, which can be installed outside the bathroom or toilet, which is safer from the point of view of electrical safety.