DIY instantaneous water heater installation: step-by-step instruction

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Tatyana Zakharova
Last update: March 2019

Many of us have repeatedly faced the problem of emergency shutdown of hot water. Agree, it’s rather inconvenient to heat water in a pan in order to wash dishes or take a dip. And if the family is large, then this can become a real problem.

But there is a solution - these are instantaneous water heaters. They help to increase the comfort level in urban apartments and provide country houses with hot water all year round. We will figure out how to install a flowing water heater with your own hands, which any home master can handle.

We will talk about the principles of operation of the heater and about what factors should be considered when choosing it. Consider the features of connecting electrical and gas equipment. Here you will find video installation instructions that will help you better understand the installation.

The principle of flowing water heating

If you are going to independently install water heating equipment, you must definitely get acquainted with its device and the principle of operation.

Heating water in a flow-through device is quite simple: cold water from the water supply passes through the heating elements and at the outlet has a temperature several times higher than the initial value.

For example, water with a temperature of + 10º C is heated to a temperature comfortable for taking a shower - + 36-40º C. The parameters are adjusted using the control buttons located on the front side of the case.

Water heating starts automatically, from the moment the tap is opened. Despite the miniature size of the device, it is able to provide heating to a temperature of + 50-65º C, sufficient to wash the dishes or take a hot shower.

In order for the equipment to work properly, the following nuances must be taken into account during installation:

  • the strength of the wall on which the device is mounted;
  • the necessary pressure in the water supply;
  • suitability of the electrical network.

If all conditions are met, the quality of the water heater will depend only on your skills.

Water heater device diagram
The standard diagram of the flow type heater device. Heating elements are used in heating models in overall models, and copper spirals in compact ones. A detailed diagram is presented in the product datasheet

Factors for choosing a water heater

If you have already decided that a instantaneous water heater suits you completely, you need to decide on the right model.

To do this, try to clarify the desired characteristics of the device, that is, analyze the following information:

  • number of permanent residents;
  • the maximum volume of water flow with the simultaneous inclusion of all points of tapping;
  • the total number of all water points;
  • desired maximum heating temperature;

Data collection will help calculate equipment capacity. It is better to rely on information provided by the manufacturer. If gas is supplied to the cottage, then you should think about connecting gas column, and if you constantly live in the house, then a gas boiler.

Temperature Rise Calculation Chart
Schedule for calculating temperature increase data for an AEG RMC instantaneous water heater at a temperature of tap water + 10 ºС and a voltage of 220 V

In residential buildings with a storey of over five, the installation of gas equipment is strictly prohibited. In this case, the choice is predetermined - you need to buy electric water heater. He will “save” during seasonal shutdowns of hot water.

Owners of private houses that do not have the ability to connect to systems with main gas will have to give preference to electrical options for equipment that treats sanitary water.This is the case if it is not planned to use bottled gas or install a gas holder.

For self-installation, the degree of installation complexity, the cost of the device, initial equipment, the ability to quickly repair and the availability of spare parts, warranty service conditions and the warranty period are also important.

If the seller offers installation services, consider this option, especially when buying an electric pressure model or gas column.

Optional with arguments selection of instantaneous water heater Another article, which we recommend reading, will introduce you.

Reasons for self-installation

Do-it-yourself installation of a device that is directly connected to the water supply system and the electrical network is a responsible and serious matter, so it is better for inexperienced users to trust professionals.

However, there are several reasons that allow self-installation:

  • cash deficit to pay for services;
  • the need for urgent installation of the device;
  • a desire for training and the acquisition of new skills (preferably under the supervision of a specialist);
  • prospect of repair or replacement.

Of course, if you yourself will understand the device of the water heater, study the instructions and install it, in the future, repair or replacement of worn parts will become commonplace.

In addition, there are special life circumstances that force you to learn to do everything with your own hands. For example, living on a remote farm, from which the nearest service center is more than 300 km.

Electrical Model Installation Instructions

So, we’ll try to figure out how to properly install a flow-through water heater with your own hands, so that it works much longer than the period specified in the warranty card. But remember that general recommendations must be supplemented with the guidance set out in the technical documentation.

Step 1. Preparatory work - mains check

Not every electrical network can withstand the power of your chosen model. On the market are water heaters with an average power of 3 kW to 27 kW. Old wiring is enough for weak devices to work, but only a new network and connection through an RCD can provide a powerful pressure head heater.

Technical data table
Technical data table that facilitates the diagnosis of the mains and the choice of wire cross-section. When laying new wiring, the manufacturer recommends that local regulations and standards be considered.

Thus, to connect most of the flow-type water heaters, a stationary installation method, an alternating current mains with a voltage of 220 V, a three-core copper cable with a minimum cross section of 3 mm X 2.5 mm, automatic protection 30 A.

Do not forget about the required grounding. If the appliance is fixed to a heating wall, the cable cross-section should be increased.

Step # 2. Choosing a place to install

The installation location depends on the type of equipment. Non-pressure type water heater usually mounted near the point of water consumption, that is, above the sink, under the sink or on the side of the tap. If the non-pressure model, in addition to the gantry crane, is equipped with a hose with a shower nozzle, you should consider the mounting location for it.

Bathroom installation diagram
Installation diagram of a flowing water heater near a sink / bathtub or shower. The main condition for installation is the availability of the control unit

Labeled Models IP 24 and IP 25 initially protected from direct water ingress, however, it is better to place them where there is no threat of water from the shower - under the sink.

At the same time, they should be available for switching on (mechanical), adjusting the pressure and temperature - which means that they should be located near the shower or sink. Therefore, installing a instantaneous water heater in a toilet is a bad idea, in a bathroom it is a good idea.

The choice of pressure device dictates other conditions.Usually it is installed near the point of draw-off, which has a maximum load, or near the riser. A powerful water heater is able to provide hot water to the kitchen, bathroom, shower, so the place is chosen based on the feasibility and ease of maintenance.

Installation diagram for pressure water heater
Installation diagram of a flow-through pressurized water heater: while hot water is in the water supply, taps 3 and 4 are in the closed position, when the hot water is turned off, taps 3 and 4 must be opened, and tap 1 closed

Such devices do not need constant adjustment - they are programmed.

Step # 3. Wall Mounting Procedure

Wall mounting consists in drilling holes and hanging the device using special hinges or brackets included in the kit.

Two main conditions for proper installation:

  • the strength of the wall (ideally fit brick, concrete, wood, conditionally - drywall);
  • ideal horizontal position relative to the planes.

If the equipment is tilted, there will be a risk of air congestion, and in the future - breakdown. The fact is that the heating elements during operation must be completely covered with water. Due to the skew of the device, part of the spiral or heater may dry out, and the mechanism will fail due to overheating.

Wall Mounting Diagram
Schemes that help to properly fix the water heater on the wall. Pay attention to the dimensions of the fasteners (dowels, screws or screws) and to the features of the wiring diagram

As you already understood, installation requires a drill and certain drills - for concrete or wood.

The procedure is as follows:

  • Set the water heater switch to the off position.
  • Take the mounting plate (should be included), attach to the wall and mark the location of the holes.
  • Drill holes.
  • Insert the dowels and screw in the screws.
  • Open the housing cover, make holes for water supply.

The next step should be carried out, taking safety measures, since you have to work with electricity.

Step # 4. Electrical connection

Make sure that there is no voltage in the network, and insert the power cable through a special hole in the rear wall, covered with a rubber plug. Hang the device on the already prepared screws, check for horizontal deviations.

Strip the ends of the wires in the standard way and insert the three wires into the terminal box. Tighten the fixing screws so that each wire is firmly fixed. Make no mistake in the color coding of wires.

Cable connection
Do not forget that the proximity of electricity and water is one of the most dangerous for human life, so clearly follow the installation diagram from the manufacturer's instructions

Installation is prohibited if there is no grounding and automatic residual current device (RCD). If a leak or malfunction occurs in the system, the machine will immediately respond and break the electrical circuit.

The installation site of the RCD is the distribution panel, which is located on the floor or in the utility room, if it is a private house.

Step # 5.Water Connection Options

Usually there are several connection options. For example, the same model can be installed above the water supply unit (top connection) and below, under the sink (bottom connection), connect the device to closed or open pipes. There are two holes in the device body for piping pipes - hoses with hot and cold water are inserted into them.

Water connection
Connection schemes: 1 - to hidden pipes; 2 - to open pipes. In the first diagram, you must first set the corners (B), then attach the hoses with gaskets (A). In the second diagram, install the holders (A) on the pipes, connect them with hoses with gaskets (B)

Low power electric water heatersfocused on one point of water consumption, usually instead of hot water entering the common line, they have a hose with a shower head.

Correct installation of a water heater
For single-point models, there are special installation instructions: the first figure shows the correct installation, the second shows the wrong one. Installing a valve at the water outlet is strictly prohibited!

The water heater can be connected both to the pipes of the central line and to the storage tank, which is 4 m (at least) above the installation site of the device. When supplying water from the tank, constant monitoring of the water level will be required.

A direct connection to a well or a well (in country houses) is also practiced, but only through a rough filter, otherwise the manufacturer will void the warranty.

How to install a gas water heater?

The installation of a gas column differs from the installation of electrical equipment in a large number of requirements and a more complex connection process. However, time and effort is offset by savings in fuel costs — cheaper than natural gas than electricity.

Step 1. Harmonization and compliance

To install gas water heater, you will need to bring gas to the house (in some regions - the most expensive cost item), then draw up a competent engineering project and coordinate it in certain instances. Designing a project should be done by a licensed organization.

About the procedure for connecting a private house to the main gas supply system in detail written here. We recommend that you familiarize yourself with the information provided.

To imagine what the requirements are for the installation, you can look at the documents of title:

  • General provisions for the design and construction of gas distribution systems of metal and polyethylene pipes (SP 42-101-2003).
  • Gas distribution systems (SNiP 42-01-2002).

The basic rules for installing gas equipment include the volume of the room - at least 7.5 m³ and the height of the ceilings - at least 2 m. A prerequisite is well-established ventilation. The minimum diameter of the chimney is 110 - 130 mm (depending on the requirements of the manufacturer).

Minimum installation diagram
Minimum distance diagram for installation in the kitchen. As a sample - a gas instantaneous water heater Therm 6000 O of the famous German manufacturer Bosch

Everyone who wants to install a gas water heater with their own hands should understand that the device without installation by representatives of a licensed organization (authorized service center) is completely removed from the warranty and free maintenance.

Step # 2. Rules for dismantling the old gas boiler

The process of replacing a geyser is faster than installing a new water heater, since no chimney equipment or connection to a gas main is required.

Progress is as follows:

  • Close the tap on the gas supply pipe to shut off the gas supply.
  • Unscrew the nut fixing the flexible hose, carefully remove it. If the column is connected in the old way of connection through a metal pipe, you will have to saw it with a hacksaw for metal.
  • It is better to discard the old connecting fittings by purchasing a modern, durable hose.
  • Turn off the water system - for reliability, it is better to turn off the taps at the riser.
  • Remove the exhaust pipe, carefully remove it from the chimney.
  • Carefully remove the device housing from the wall bracket.

In the process of dismantling, try not to damage the supply pipes, otherwise the replacement of the water heating device will result in the replacement of all adjacent equipment.

Pipe connection
Modern geysers (instantaneous water heaters) have a mandatory triple connection: to the gas pipe, to two pipes with water (cold - inlet, hot - outlet), to the chimney

If you notice wear on the pipes, it is better to replace them with new ones - most likely, more reliable models have appeared in stores during the operation of the old device.

Step # 3. Installation Instructions for the new gas model

First, check the chimney. Check the tightness of the joints, the vertical arrangement of the pipe for the removal of gases, the quality of thermal insulation. Do not forget that the outlet must be above the highest point of the roof and be protected from rain by a visor.

Which pipe you will use - flexible or rigid - does not matter, rather, its characteristics depend on the installation conditions. Then check if the ventilation is faulty.

Geyser Connection Option
One of the standard options for connecting a geyser, designed to provide hot water to two water consumption points - in the kitchen and in the bathroom (+)

Correct the mounting locations for the new model. Remove the handle of the switch (power regulator), unscrew the fasteners holding the casing, and remove the front of the case. Use mounting loops, screws and wall plugs to hang the column on the wall. Remember: the case must hang freely on the wall, and not stand on the water or gas inlets.

Use flexible hoses to connect the device to a cold water pipe, then connect the outlet to a hot water tap.

Water connection diagram
Water connection diagram. To mark the connection points for cold and hot water (A and B), they are marked in blue and red. To control inlet pressure drops, the manufacturer recommends installing a check valve.

The next step is to connect the gas. Use a flexible hose to connect the gas valve to the inlet to the water heater. You can verify in the traditional way, soaping the junction and opening the gas supply.Lack of bubbles indicates proper connection.

Lastly, a chimney pipe is installed. Most often, this is a flexible corrugation, selected according to the diameter of the outlet. Fix one end of the corrugation at the outlet of the column, insert the other into the chimney. Replace the front panel with the switches, tighten the fasteners and test the device.

Operation and Maintenance Rules

Malfunctions can appear both in a few years, and in a month. The risk of breakdown is especially great in case of malfunctions of the device.

In order for the electrical equipment to work properly, it is necessary to monitor the cleanliness of the filter and clean the aerator from time to time. About once a year carry out maintenance work: turn off the water heater, remove accumulated dirt, blow pipes. Tighten the mounts if necessary.

At geysers, monitor the cleanliness of the heat exchanger, change the gaskets, clean the burner and ignition nozzle, change the water filters.

If maintenance and the simplest low power appliance repair can be done on their own, it is better to entrust the control of the gas service with which a contract is concluded to control the operation of a gas water heater.

Especially not worth the risk if there is a problem of insufficient pressure of water, clogged water fittings or the heat exchanger is covered with limescale.

Conclusions and useful video on the topic

Three informative videos will introduce you to the secrets of installing instantaneous water heaters and prevent issues that often arise during the installation process.

Video # 1. Installation instructions for electric water heater Stiebel Eltron DHC:

Video # 2. How to install a CLAGE DSX instantaneous water heater with remote control:

Video # 3. Professional installation of a geyser:

As you can see, you can install a flowing electric or gas water heater yourself, using the manufacturer's instructions or useful videos. However, maintaining the warranty and increasing the life of the device is only possible with the help of professional service.

Have questions while familiarizing yourself with the information we have proposed? Is there any useful information that you would like to share with visitors to the site, or a photo on which you recorded the steps of your own installation? Please write comments in the block below, here you can leave files with pictures.

Was the article helpful?
Thanks for your feedback!
No (13)
Thanks for your feedback!
Yes (83)
Visitors Comments
  1. If possible, then it is better to consider the option of buying a gas instantaneous water heater. It is not only a lower cost of operation, but also a better and stronger heating of water even with cheap samples. Moreover, there is no risk of contact between water and electric current. Electric versions of low power do not heat the water so much, their power is not always enough for a normal swim.

    • Expert
      Alexey Dedyulin
      Expert

      Hello. The gas column has its drawbacks. If the water pressure is poor, it simply will not light up and there will be no hot water supply, while the electric boiler draws and heats water, you must always control the draft, again, there is an explosion and fire hazard from the column + weakness in the quality of the water.

      It was such in my experience that, out of stupidity, the column was turned on to the fuse during bathing, and as the water cooled, hot water was opened, and the column was turned on, respectively. But it turned out that dirty water went from the central water supply system and clogged the system.The column began to boil and began to spit boiling mud.

      As for the contact of water and current, well, in general, many modern speakers have electric-dependent functions. Any system needs constant diagnostics, just to whom it is convenient.

  2. Victor Simonov

    Help in this situation, maybe someone came across? In general, about six months ago I decided to abandon central heating, switched to individual. I put a boiler in the bathroom, and a flowing water heater in the kitchen, since the kitchen only needs warm water for washing dishes. After installing and connecting the water heater to the network, it began to periodically knock out electrical machines. With what it can be connected, how to solve?

    • Expert
      Alexey Dedyulin
      Expert

      One of the three - either the wiring is weak and needs to be changed (the most unlikely case, but it happens), either the machine does not cope with the tasks assigned to it (more likely, especially if it has a bunch of everything else besides the water heater), or the device itself is defective. Rather, the case in the machine. At such power, it is generally recommended to conduct a separate machine.

  3. You have a lot of voltage in the network, because water heaters are energy-intensive, therefore either automatic machines are too small for these water heaters, or wiring of insufficient cross-section. Try insulating the wire when you turn on the water heater: it will be warm or cold. If the wire heats up, then you have to change it - the cross section requires more. Do not delay with this, otherwise it is not far from a fire. If the network is disconnected, and the wire does not heat up, you need to change the machines: if they are 10a, set to 16 amp or 25a.

Pools

Pumps

Warming