Water heaters: types of water heaters and their comparative characteristics

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Maxim Fomin
Last update: May 2019

If the housing is not connected to a centralized hot water system, then you cannot do without a water heater. Many of us perceive the lack of hot water as a disaster. No wonder water heaters are so in demand in the domestic market. They are installed both in cottages and in apartments. It is only necessary to choose the most suitable device for specific needs.

In this article, we consider the existing types of water heaters, their main characteristics, advantages and disadvantages. We will also conduct a comparative analysis of water heaters to find out which option to give preference, given the living conditions and their needs.

Types of water heaters by energy source

Before choosing a heater for hot water, you need to determine the heat source for heating. Most often it is gas or electricity.

But it is also possible units that run on liquid or solid fuel. Such heating devices will only cost more than the first two options.

Gas and electric water heaters
Gas is cheaper than electricity, but gas water heating equipment is more expensive than electric in installation and operation - you should choose such equipment carefully

According to the type of energy used, water heaters are divided into:

In the first two cases, the water is heated as a result of gas combustion or the operation of a heating element. The third option is a system from the boiler and the boiler connected to it through the coil. In this case, the main boiler equipment in such a bundle can be gas, solid fuel, electric, etc.

Among the advantages of using gas are:

  • fuel cheapness;
  • equipment service life of 10-15 years;
  • high productivity and efficiency of equipment.

But for these pluses you have to pay the need to invite the master to connect the gas equipment and the obligatory arrangement of the chimney. Plus, you need a connection to the gas pipe. It is not recommended to connect the water heater from the cylinder. Balloon fuel is obviously more expensive than the pipeline analogue.

Gas water heaters come with an open atmospheric and inflatable burner. The former have natural cravings, while the latter is forced. Any of these options requires large initial costs for equipment and installation, but then quickly pays off due to the cheapness of natural gas.

Of the advantages of an electric water heater should be highlighted:

  • relatively low cost of equipment;
  • light weight and small dimensions of the water heater;
  • minimal risk of fires and explosions;
  • the possibility of self-installation of the heater.

The main disadvantage of water heating for electricity is the power limit. If a water heater is required for a family of 4-5 or more people, it is better to prefer gas technology.

Gas water heater in the kitchen
If a gas water heater is selected, then maximum attention should be paid to the automatic safety systems available in it. Gas is explosive - the more protection elements in such equipment, the better

Types of water heaters by heating method

All domestic water heaters are divided into two types - flow or storage. The first ones allow you to get hot water faster, and the second ones are more economical.

Water storage heater
Accumulating water heaters have a tank with a volume of up to 400 liters, in which the water is first heated to the required temperature, and only then it is supplied to the DHW system

Flow heaters are simple in design. If they work from the mains, it is enough to apply voltage and cold water to such a heater - and warm water immediately runs from the tap to wash and wash the dishes.

Option # 1 - flow view of the water heater

Most often, flow heaters are found in electrical performance. Inside them, a heater with a large heat exchange area is installed.

Advantages instantaneous water heater has the following:

  1. Compactness of the device.
  2. Water heating only at the time of its consumption.
  3. Simplicity of the connection scheme for hot water and cold water pipes.
  4. No restrictions on the installation site of the water heater.
  5. No noise during operation.
  6. Instant heating of used water.

But there’s also a sale gas appliances similar type.

Among the minuses of instantaneous water heaters should be mentioned:

  • direct dependence on the availability and continuity of the heat source;
  • lack of storage capacity;
  • high likelihood of scale formation on the heat exchanger.

If gas or electricity ceases to flow to such a heater, there will be no hot water. In the storage boiler, it heats up in advance and when the power is turned off, it remains warm inside for some time. In a flow device, it does not accumulate anywhere.

Running water heater in the bathroom
The main feature of running water heaters is the need to connect them to a centralized cold water supply, you should not take such models to the cottage

Option # 2 - cumulative type of water heater

Storage type heaters can operate both from a centralized cold water supply and from an autonomous source of cold water. By design, they resemble a heated thermos. This drive has thermal insulation, which allows it to retain heat for several hours without wasting energy on heating.

Storage tank with large internal tank
The larger the volume of the tank, the longer the water heats up in it. For example, it takes 2-3 hours to heat a container of 100 liters to 60–70 degrees

Among the advantages of storage heaters:

  • profitability and less power consumption;
  • stability of hot water supply;
  • large amount of stored and heated water.

Electric storage water heater with a capacity of 100-150 liters consumes about 1.5 kW. Water heating in it occurs gradually, so it does not require large capacities. Three-phase networks are usually not needed here. It will be enough to connect to a regular household outlet.

Storage water heaters are divided into:

  • non-pressure;
  • pressure head.

The first have a small tank of 10-50 l and are designed to supply one or two water points.The second are more capacious, designed only for connection to a centralized hot water supply and provide for the installation of a pump to supply hot water to several plumbing fixtures in the house.

Storage boiler device
The boiler is designed so that cold water enters it from below, and hot water is taken from above - this further reduces the energy consumption for heating

The water tank is made of stainless steel, covered by:

  1. Glass-ceramic (glass-porcelain).
  2. Titanium enamel.
  3. Plain enamel or glaze.

The most durable tank with titanium enamel. However, it costs more than other analogues. Glass ceramics are not susceptible to corrosion, but at high temperatures tend to crack, which leads to failure of the drive.

The stainless steel itself tolerates thermal expansion, but sooner or later it begins to rust. If the protective layer on it is cracked, then the tank can be safely changed. He will not last long after that.

Detailed recommendations for choosing a storage water heater are given in another our article.

Another mandatory element of the boiler is a magnesium anode. It protects the inside of the tank from corrosion and scale. This is a consumable item that needs to be changed at least once a year. However, saving on it is not recommended. To replace due to a malfunction of the heating element inside or completely of the boiler will be known to be more expensive.

Manufacturers give a guarantee for such a tank for 4–5 years. But if the magnesium anode is defective or not, then the drive will last a year from the strength. High temperatures and hard water will do their “rusty” thing.

To find out more information about water heater breakdowns and how to eliminate them, please go to this page. the link.

Comparison of DHW heaters

When choosing a water heater, the following model parameters should be compared in the data sheet:

  1. The type of energy source is electricity or gas.
  2. Water heating time.
  3. Tank volume (for storage boilers).
  4. Power characteristics (for electric water heaters).
  5. Productivity in liters / minute (for flowing devices).
  6. The maximum heating temperature is from 50 to 80 ° C.
  7. Type of device by location.
  8. Features of the connection.

Easiest on their own install and connect electric flow heater with power up to 4–5 kW. You just need to connect a pair of hoses to the domestic hot water supply and the domestic hot water outlet, and then turn on the device in the mains.

Gas boiler connection
To connect a gas water heater, you will have to invite a specialist from the supplying organization - it is forbidden to independently connect such equipment

By the method of arrangement of water heaters are:

  • horizontal
  • vertical
  • combined.

They are mounted on the wall, placed on the floor or built into cabinets. At the same time, storage boilers with a large tank are only available in the floor version. Not every wall is capable of supporting the significant weight of such water-heating equipment and the water in it. We talked more about installing and connecting the storage model in this article.

For each specific case, you can now find your best option. The range of modern water heaters is huge.

If a water heater is needed as a safety net in case of disconnection of hot water, then it is worth taking an inexpensive and compact flow-type model. Other variations in this situation will be redundant.

Small electric heater for summer cottage
For summer cottage it is recommended to take a small storage boiler with a tank of 30-50 l - it is enough to wash in the morning, take a shower and wash dishes in the kitchen sink

If the family consists of three people, then she will need a drive volume of 100-120 liters. In this case, installing a flow device is not worth it due to the large consumption of water and electricity consumption. Moreover, if a water heater is needed in a large cottage and there is a gas main, then gas-fired equipment will be out of competition.

For a large family, you can also take a combined type of boiler - a storage tank plus a flow-through heat exchanger. If the first at some point is completely empty, then the second is included in the work in it. This avoids waiting until the tank is full and warms up. At the same time, energy consumption is reduced due to the presence and regular use of just a storage boiler.

The more powerful the water heater, the more efficient and faster it will produce water of the required temperature. However, at the same time, its consumption of electricity and gas is growing. This is especially true for electric heaters. It is one thing to connect a similar device to a 220 Volt outlet in the bathroom or in the kitchen, and it is completely different to pull a separate three-phase cable for it.

Conclusions and useful video on the topic

Pros and cons of various water heaters:

Tips for choosing and installing a water heater:

When choosing a water heater, you should focus on the volume of water consumed and the availability of a particular energy source for the operation of such a device.

With a small water consumption, a flowing electric heater will be enough. But for a large family, it is best to put an accumulative analogue on gas in a cottage.

What kind of water heater do you use? Are you satisfied with its characteristics or are you thinking of a replacement?

If you are just choosing the right option for your water heater and want to clarify a number of nuances, ask questions to our experts and other visitors to the site in the comment block under this article.

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Visitors Comments
  1. Kirill

    Better than a geyser or a double-circuit boiler have not yet come up with anything. However, if there is no gas or the project is not provided, it is better to put a simple storage electric water heater with a capacity of 100-150 liters to help. For example, I already have the second tank at 150 Gorenje, the first is over from old age - I worked for 12 years and drip. Now purchased composite. Parents have gas - here, of course, everything is more and more positive, starting from the speed of heating, and ending with the cost of energy.

  2. taukita63

    I would also attribute to the disadvantages of an electric boiler a large consumption of electricity. If for rural areas, where tariffs are half as much, this is quite acceptable, but for the city it is still relatively expensive. The boiler tank also needs periodic cleaning, especially if the water is not quite good. As for gas options, they do not seem completely safe.

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