How to choose an inverter for a heating boiler: selection criteria + review of reliable models

Many modern heating systems are controlled by automation and require a constant supply of electricity for proper operation. If regular power outages occur with the energy source, experts recommend buying a backup generator. When the lack of electrics is rare and does not last long, it is enough to install a progressive inverter for the heating boiler.

It turns the direct current coming from the battery into alternating current and allows the heating equipment to fully function for a certain time even in the absence of electricity. Let's take a closer look at the main characteristics of the device.

General characteristics of the device

An inverter is primarily a DC to AC converter. In parallel, it changes the transmission amplitude and generates an output signal of a suitable frequency. The device itself cannot charge the battery and control its current capacity.

Many modern manufacturers equip their products with related elements, additional chargers and a control control unit. Such models are already classified as uninterruptible power supplies (UPS) and have the ability to solve a wider range of tasks.

Manufacturers give a big guarantee for the uninterrupted operation of inverter equipment for boilers - from 10 to 12 years with 600-620 active cycles and battery discharge at the level of 80-83%

Integrated into the heating system, they monitor the presence of current in the network and, in the case of a sudden emergency outage, electricians, for some time, maintain the full-fledged operation of the equipment.

In this way, preventing the potential freezing of water in pipes and radiators (in the winter season), breakdown of individual fragments of the system and other unpleasant problems.

The inverter, equipped with an additional battery, allows heating equipment to work for a long time and efficiently even with a prolonged absence of a centralized supply of electricity

Simple, low-cost products perform only one direct function - providing the boiler with energy to work for a certain amount of time. Sophisticated progressive modules have enhanced potential.

In addition to their main mission, they act as stabilizers and equalize the voltage in the system, thus protecting the equipment from unnecessary load and failure.

Complete set of invertor energy sources

In the modern market of household related equipment, inverters are available in several versions. Some brands produce the simplest units that work only as voltage converters.

The battery is not initially included in the package of such modules, but its connection is allowed by the design, and the user can buy this element separately in the future.

Inverter equipment should be purchased only at the regional official representative office of the manufacturer. There, in addition to the product, the buyer will be given a warranty card for service and, in case of malfunctions detected in the first working days, they will replace the product with a working one

Some types of inverters have a built-in battery of a certain, as a rule, small capacity, however, increasing its volumes due to external additional batteries is not possible.

Devices of this type support the operation of heating equipment for a short time and for the most part serve to ensure that the owner can correctly disconnect the system from the power supply in an emergency.

A universal battery is built into universal units. The capacity expansion of the device is carried out by adding external batteries. In this way, the duration of the device is increased from several hours to several days.

Product design features

The inverter has optimal dimensions and resembles a box. It is placed on the floor in the immediate vicinity of the boiler or mounted on the wall (if this is provided for by the structural features of the purchased model).

The working battery transmits a direct current of 12 V. The inverter absorbs it and converts it into alternating current with a traditional voltage of 220 volts, and also monitors the degree of charging of the battery itself

In advanced models, a control unit with a boiler switching system and a basic battery are located inside the case. The first node controls the availability of energy and timely switches the equipment to an autonomous mode of operation if interruptions occur in the central network with the supply of a resource.

The second unit (battery) provides power to all electronic components of the boiler for the entire period of power outage or until the moment when the charge runs out.

How are appliances classified?

Almost all inverter devices are components of a UPS (uninterruptible power supply) and perform the same function - they convert the direct current from the battery to alternating current.

In the event of an unexpected blackout, the backup power supply system is activated, and the heating equipment instantly switches to stand-alone operation. This allows you to maintain the full functioning of the heating over a certain time period - from several hours to several days.

According to the principle of action, the devices are divided into three types:

• Off-line (backup);
• Line-interactive (linear-interactive);
• On-line (double conversion).

Each type of device has its own specific characteristics and capabilities that allow solving diverse problems. After a thorough study of the parameters of all three devices, choosing the best option for yourself will not be difficult.

The principle of operation of units Off-line

The off-line model has a simple design and is considered redundant. When the power supply operates in the standard mode and demonstrates stability, and the voltage does not “jump” between the extreme values, the device “sleeps” and does not participate in the operation of the household heating system.

If the current level drops to 175 V, the unit transfers heating boiler to recharge from the battery. As soon as the situation is restored, the inverter UPS reconnects the heat engineering back to the main network.

Off-line device is ideal for working in conjunction with a gas heating boiler, but only if there is no problem with voltage stabilization in the central power supply

Each transition from the main power source to an autonomous one and vice versa lasts no more than 10-15 seconds and does not affect the functionality of heating equipment.

The operating range of most off-line converters lies in the range 170-270 V.

Progressive inverter converters are usually equipped with informational liquid crystal displays and current regulators. They do not have an active cooling system. Due to this, the work process is absolutely silent and does not interfere with irritating sounds to residents

With a constantly “jumping” voltage, switching from the main system to the autonomous system occurs too often and leads to rapid wear of the batteries and the device itself. Stabilizers are not included in the package of the device, therefore, when connecting, both at the input and output, the mains voltage does not change.

Therefore, we recommend reading our article on how to choose a voltage regulator for a heating boiler. Read more - read Further.

Depending on the manufacturer and model, backup devices can work effectively with electrical equipment with power from 300 to 3,500 watts. In some products, cyclic functioning and the ability to prevent freezing of communication fragments of the heating system during one day or more are provided.

How do Line-interactive modules behave?

Line-interactive (Line-interactive) device is a switching type device and is considered the best option for universal equipment. Structurally, the product consists of an off-line source, a converter, a switching relay, and a low-frequency stabilizer device.

In the standard operating mode of the unit, the heating equipment consumes the resource of the central energy highway. The output voltage is controlled by a stabilizer and special filters (on some models), which smooth out the noise and neutralize the noise of the network to which the boiler itself is connected.

A gas boiler connected to a line-interactive converter equipped with an additional external battery can last from 8 to 10 hours (depending on battery capacity)

The units of the linear-interactive type supply useful energy to electrical appliances for a very short period of time (no more than 20 minutes).

To provide a resource for heating boilers, not ordinary linear gauges are used, but advanced products with an expansion function that provide for the connection of an additional external battery. Such devices can support the operation of the boiler for a longer time (up to 10 hours, depending on the manufacturer).

The line-interactive converter puts the battery into operation extremely quickly (in about 2-4 seconds). The output stream of the device can be pulsed or sinusoidal. On the heating boilers, experts recommend putting the second option

The built-in current stabilizer allows the equipment to work correctly without switching to a battery with an extended voltage range. The device provides backup power from the battery and equalizes the mains voltage. The disadvantages of the products include the impossibility of correcting the flow frequency of the current and the minimum smoothing of the sinusoid (no more than 20%).

Features of on-line devices

Online appliances operate continuously.

The conventional scheme for connecting heating equipment in this embodiment is built in the following sequence:

• central electric network;
• inverter uninterruptible power supply;
• boiler.

The principle of operation of the device is to re-convert the general parameters of the electrical network. At the first stage, when entering the inverter, the alternating voltage is converted into a stable equivalent with a value of 12 V.

Then the reverse maneuver takes place and at the output from the inverter apparatus the voltage turns into an alternating one with a value of 220 V.

In online systems, the battery performs a buffer function and is constantly recharged. At the same time, the output converter is activated inside the battery and forms an alternating voltage with indicators of 220 V 50 Hz from a constant voltage, which does not depend on the voltage generated at the input

The main advantage of a system of such a plan is the provision of a power supply for the heating boiler with high-quality voltage. Among the minuses there are only two positions: the high cost of converting equipment and the low level of productivity.

Advantages and disadvantages of equipment

The inverter is convenient in that it is not tied to a certain type of constant voltage source. The unit can be powered using a conventional car battery, a generator set with a simple signal rectification principle, or from UPS batteries.

If the module does not have a built-in charger, the owners will have to personally control the level of capacity and the degree of discharge of the device.

Among the main advantages of the device:

• a wide range and the ability to choose a product with an almost perfect output sine wave;
• correct operation with all sources of rated voltage and direct current;
• reasonable cost in comparison with other similar units of similar power;
• lack of restrictions on increasing battery capacity and the duration of autonomous functioning.

Disadvantages include criteria such as:

• lack of control over the level of charge / discharge of the battery;
• setting the threshold is not subject to additional correction;
• the need to equip an external communication circuit for automatic activation when the electricity is cut off in the living room;
• the high cost of "sophisticated" modules with a wide range of features.

The final selection of a suitable device is strictly individual. It all depends on how much voltage “jumps” in the network, how often the central electrical system disconnects consumers from the supply of the resource, and how long it takes to sit without light.

Basic rules for choosing a module

When planning the purchase of an inverter for a boiler, you need to pay close attention to such parameters as:

• indicator of input voltage and current;
• output voltage level;
• the degree of distortion of the sine wave of the output voltage;
• actual conversion rate;
• total output power.

For household gas boilersmainly use inverter units 12-220. These units convert the DC voltage of a 12 V battery into a sinusoidal voltage of 220 V with minimal distortion.

The sine wave of the inverter output voltage must not exceed 3%. These indicators mean that the waveform is as close as possible to the sine with slight deviations towards a sharp decline or cut peaks

You can get a more powerful bunch of units (a 24-220 converter and a 24 V battery), but you need to find out exactly what maximum input current the inverter is designed for.

Only after receiving this information is it worth starting the purchase.

Inverters, offered on the domestic market, were initially designed for low quality electric networks. The units have all the functions of protection against energy surges and an option that allows the user to set the upper and lower voltage limits up to volts

The controller and control unit of popular gas boilers usually consume power of about 150-200 watts. Responsible for the correct circulation of the heating fluid in the system, circulation pump takes another 125-150 watts. To determine the indicator of the required inverter power, these data must be added and multiplied by 2.5 to take into account the amount of starting current at the time of starting.

The finished numbers must be multiplied by 1.2 again to take into account some power reserve. The received data should be memorized or recorded. When buying an inverter, make sure that the base power declared by the manufacturer certainly exceeds the calculated indicators.

List of popular models and manufacturers

A lot of domestic and foreign companies, firms and organizations work in the segment of the electrical engineering market. Some of them produce products under license, others develop their own technologies and offer customers unique, progressive and competitive products at a very reasonable price.

The device of the company ETK "Energy"

The PN-500 Energy inverter is an inexpensive practical device that provides uninterrupted power supply for modern low-power boilers. Manufactured at the production facilities of ETC Energia, one of the leaders in the domestic electrical market.

Inverters ETK "Energy" fully comply with all GOSTs and requirements for household electrical equipment. Environmental safety and product quality are confirmed by internationally issued certification certificates.

Connection to the device of one basic battery provides full autonomous operation of the fuel boiler for 6-7 hours. If you connect a second battery, the operating time will be doubled.

The unit produces a pure sine at the output, contributing to the preservation of the expensive electronic "filling" of modern heating boilers. When the operation of the central electrical system is normalized, the inverter switches to voltage stabilization mode on its own and protects the boiler from sudden voltage surges.

The Elim-Ukraine device

The company "Elim-Ukraine" has been operating in the market of electrical equipment for more than 10 years and is respected by customers.

Devices released under this brand have a switching power supply, an LED display that is pleasant to the eye and demonstrate an extremely high level of efficiency (up to 98%). They produce a pure sinusoidal signal without distortion and peak levels of overvoltage.

Elim-Ukraine inverters are also convenient because they work correctly with both gel and car batteries

Equipped with protection against overheating, general overload and deep discharge of the battery. One of the expansion options allows you to connect an additional battery of any capacity to the equipment to maintain the autonomous operation of the heating system even if there is no voltage in the central main networks for a day or more.

Unit Rucelf UPI-400-12-EL

The Rucelf UPI-400-12-EL device belongs to the category of linearly interactive energy sources. It has a built-in stabilizer, which even if there is a minimum mains voltage equalizes the current flow without using the battery. This makes it possible to economically consume battery life without overloading and prolonging their service life.

Important advantages of Rucelf UPI are completely silent operation and efficient provision of devices with necessary power during an emergency power outage

Reasonable cost is another characteristic feature of the products of the Russian company Rucelf.

Thanks to this, customers can create a full-fledged autonomous infrastructure for feeding heating systems during an emergency power outage or power surges.

Conclusions and useful video on the topic

How to buy an inverter and choose the optimal battery for it. How to install equipment on the boiler and forever forget about interruptions with the electrician:

A detailed review of the device, the principles of operation and functionality of the popular model of an inverter voltage unit with a pure sinusoid:

How an inverter voltage converter does not have a built-in battery inside the case:

The installation of an inverter device in a heating boiler allows the heating system to function correctly at the time of intense voltage drops and with a general blackout. The owners do not feel any inconvenience due to lack of electricity and do not freeze if this unpleasant situation happens in the cold season.

In addition, the device protects communication elements from possible damage caused by an unexpected blackout, and helps the equipment work as long as possible and with maximum efficiency.

Already have experience using inverters for heating boilers? Please tell our readers which device you chose? What guided this? Are you satisfied with the operation of the device? Leave your comments, share experiences, ask questions in the block below.