Electricity Consumption Of Gas Boilers: How Much Electricity A Typical Heating Unit Consumes

It may come as a surprise to some that gas-fired boilers not only need gas but also electricity. And along with the gas consumption you should also consider the electricity consumption of the gas boiler, which is the heart of your heating system.

Now there is bound to be a reader who will object and will be right. And he is right in the fact that there are still gas boilers with no connection to the power grid. These are classic floor units with open combustion chamber, they require a separate room and strict compliance with stringent rules of fire safety.

Independent boilers are currently used in remote villages, cottages - where there are interruptions in electricity supply. Or when you want to save money on the purchase of equipment. But we shall talk about modern gas heating appliances, which only work with a high quality and reliable power supply.

Accompanion to this article:

  • What does the gas boiler need the power for?
  • The electricity consumption of a gas boiler in figures
    • Minimum power consumption
    • What does the data sheet of the gas boiler say?
    • Calculation of the electricity consumption   an example
  • How to cut the electricity costs?
  • UPS for gas boiler and its electricity consumption
  • Conclusions and useful video on the topic

What does the gas boiler need the power for?

When the closed combustion chamber appeared gas appliances became dependent on the electricity network. Electricity consumption in such boilers is determined by the composition and amount of electronics in its innards.

And they are no longer allowed to be installed only in an insulated boiler room, but also in kitchens, bathrooms. From the safety point of view they have a high level of protection.

Electricity consumption of gas boilers: how much electricity a typical heating unit consumes

The arrows mark the main electrical consumers of the wall mounted gas boiler - the air blower and the built-in circulation pump. In systems with a floor standing boiler the pump is installed separately, but in general more than one pump can be used in the heating system and all of them will consume electricity

Let's list what exactly requires energy consumption:

  • electric ignition;
  • circulation pump;
  • closed combustion chamber fan;
  • automatics (gas control as well as draft, gas pressure, water pressure sensors, etc. ).

The gas boiler with electric ignition is ignited automatically by an electric spark. The ignition wick, which burns continuously in other ignition systems, does not burn at all, no gas is wasted.

The moment the electric spark ignites, some electricity is expended, but the moment itself lasts a fraction of a second. This consumes very little electricity, the gas savings due to the absence of an igniter covers these costs. The only disadvantage is that in the absence of electricity the boiler equipment cannot be started.

If the power supply in the network disappears suddenly, the gas cut-off device is triggered. When the power comes back on, the electric ignition will restart the heating system without human intervention.

Circulation pump - that's what raises the power consumption dramatically! But minimizing costs when operating a gas boiler is realistic if you use thermostats in all rooms, building them into the overall circuit of pump power and boiler operation.

Ether economic result greatly increases the programmer. The thermostat only helps to maintain a stable set temperature, while the programmer is able to set the day/night mode of operation, changes by day of the week, etc.

Electricity consumption of gas boilers: how much electricity a typical heating unit consumes

Modern gas boiler automatics need electricity and are sophisticated electronic devices which, without human intervention, regulate the fuel supply and the flame intensity of the gas burners, control the temperature, diagnose malfunctions

The fan (turbine) in a closed combustion chamber also consumes electricity, but less than the circulating pump. The expense is justified  by improved smoke extraction. Boiler with coaxial chimney does not burn oxygen in the room, does not let out carbon monoxide and makes less noise.

Automatics in a gas boiler increases its final cost, but with it the heating system control is reduced to setting the desired temperature and pressing just one button.

Electricity is needed for the operation of the controller that regulates the gas supply and the many sensors. Its consumption depends on how sophisticated the automatics are, but in general we are talking about low-cost energy consumption.

Electricity consumption of a gas boiler in figures

Everyone is usually interested first of all in the consumption of gas. And the question of how much electricity the typical gas boiler consumes, sort of goes into the background. Let's deal with it.

Energy-dependent gas boiler is connected to AC power with standard characteristics: 220 V and 50 Hz. For stable operation of the unit, it is important that the voltage does not drop beyond the 195V mark. At lower voltages, the electrical components will malfunction and start shutting down.

Minimum Electricity Consumption

Electricity requirements vary during different phases of operation. The minimum electrical consumption of a gas boiler is 65 watts. This is during the operating phase of the circulating pump and during the electrical ignition it is 120 W, i.e. almost twice as high. If the fan is switched on, it consumes also electric power - another 30-35 W.

Electricity consumption of gas boilers: how much electricity a typical heating unit consumes

Easy boiler start, gas savings and safety due to the lack of permanent ignition are the main advantages of the gas boiler with electric ignition, ignition requiring electric power

We deduce. The electrical ignition requires 120 W, then with the pump and fan running the electricity consumption will be:

65 + 30(35) = 105(110) W

This is the minimum daily electricity consumption. Here the electricity consumption of other parts of the heater, that is the automatics, is not taken into account. Even if not very much, but the final result will be higher.

It should also be mentioned that the figures are given for a single-circuit unit, i.e. only the heating without the hot water supply is taken into account. If you take the same thermal capacity, but a two-circuit boiler, the electricity consumption will be higher.

What does the gas boiler data sheet say?

Any gas boiler data sheet contains information on electricity consumption. Having studied the technical documentation of Bosch, Baxi, Vaillant, Ariston and other products, we can see that the electric power of floor standing units is in the range of 100 to 200 W, and of floor standing ones - from 15 to 160 W.

But since the heating systems with floor standing boilers are often equipped with separately installed circulating pumps. It is important not to forget them and to consider the additional electricity consumption.

A comparison of the electricity consumption in the presence of DHW (dual circuit boiler) and without DHW (single circuit boiler): A floor standing single circuit boiler of 30 kW consumes 15 W, a double circuit boiler also of 30 kW - already 150 W.

Electricity consumption of gas boilers: how much electricity a typical heating unit consumes

It can be seen from the technical data that the bigger the heating power of the gas boiler, the higher its electricity consumption

Different manufacturers describe ambiguously in the characteristics of gas boilers their electricity consumption.

It can be one general line or in detail:

  • pump electricity consumption;
  • electric power without pump;
  • stop losses;
  • stand-by consumption.

Consumption for all items is given in watts.

Calculation of the electrical consumption  by example

To calculate the kilowatts of electricity consumed by the gas boiler, we do the classical electrical consumption calculation, the same as for the other electrical appliances. Based on the electric power of the boiler, indicated in the technical certificate. This parameter is given by the manufacturer with the maximum value, which in reality is higher than the average actual value.


Let's say we have a single-circuit gas boiler Baxi Luna 31.310 Fi, its useful thermal power - 31 kW, electricity consumption - 165 W.

Calculate the daily electricity consumption for heating fluid preparation. Multiply the power consumption by the number of operating hours of the boiler.

Let's assume that the heating is on all day long:

165 W × 24 hours = 3960 W×h or 3.96 kW×h - this is the maximum daily electricity consumption

We now calculate how much electricity in kilowatt-hours the gas heating boiler consumes per month. Multiply the number of kilowatts consumed per day by the number of days in the month (30 days):

3.96 kWh×30 days = 118.8 kWh - this is the maximum monthly electricity consumption.

Electricity consumption of gas boilers: how much electricity a typical heating unit consumes

The energy dependent boiler does not need natural air flow, because the forced ventilation works. Its control system is fully automatic and in energy saving mode the anti-freeze protection is included - periodically the boiler is switched on to warm up and the circulation pump runs the water in the system

And finally it is necessary to get the electricity consumption for the year or for the heating season. Since we are talking about a single-circuit boiler and, therefore, heating without DHW, we take the duration of the heating season to be 7 months.

Then: 118,8 kW×h×7 = 831,6 kW×h - the maximum electricity consumption during the whole heating season.

For a two-circuit boiler we have to include 12 months in the calculation - although in economy mode, the boiler also works in summer months.

How to reduce electricity costs?

We proceed from the fact that, first, electricity consumption directly depends on the thermal capacity of the heating boiler. And secondly, most of the electricity consumed is taken by the circulation pump which pumps the heat carrier in the pipes so that the pipes and radiators warm up in a measured way.

Electricity consumption of gas boilers: how much electricity a typical heating unit consumes

The boiler usually always works at night from 23:00 to 06:00. Use a multi-tariff electricity meter, there are reduced rates during night hours

Let's give some specific suggestions for those who would still like to reduce their energy costs:

  1. Select an energy-independent unit. Most likely, it will be a floor standing version. In terms of functionality and comfort, alas, it is not able to compete with its power-dependent models of analogues.
  2. Buy a power-dependent unit, but of low power. Here, of course, there is a significant limitation - you cannot ignore the number of square meters to be heated. If, for example, you need to heat 180-200 square meters of private homes, the gas boiler needs a capacity of 20-24 kW. And not less.
  3. Consider carefully the assortment lines of different brands. Each model has its own nuances and maybe for some of them you will see the most attractive figures on electricity consumption in the technical specifications.
  4. Analyze the sum of total expenses for electricity payment. Maybe the share of these costs that comes from the gas boiler is negligible, and it is necessary to shift attention to other objects that really overuse electricity.
  5. How about using alternative energy - say, solar panels or collectors on the roof of the house?

And yet in the pursuit of saving electricity do not drive your own  actions to the absurd. Don't forget that gas units eat little electricity because their main fuel resource is not electricity, but natural or liquefied gas.

UPS for gas boiler and its power consumption

If there is a power loss in the network, the gas unit will switch to emergency operation, which threatens to break the expensive components. And the UPS (uninterruptible power supply) will come to the rescue in such situations.

Electricity consumption of gas boilers: how much electricity a typical heating unit consumes

How long the gas boiler can operate in the absence of electricity in the network, depends on the capacity of the battery unit. Choose either a UPS with a battery built in or a UPS with the ability to connect the right number of battery sections

The \"line-interactive\"type are the most popular UPSs, if you believe the many customer reviews. They contain a voltage regulator capable of responding to mains voltage variations within 10 percent, switching to battery power if this value is exceeded.

The \"off-line\"type is an uninterruptible power supply without a voltage regulator. They help in case of sudden power failure but do not protect against line voltage fluctuations.

The \"on-line\"238> type is the most advanced UPS. They have a smooth changeover from mains power to battery power and vice versa. The only disadvantage is that not everybody can afford the price.

The moment the gas boiler is started, the electricity consumption increases by at least two, if not three or four times. Even if it is a brief moment lasting a second or two, still take the UPS for the gas heating boiler to the maximum and with a reserve of power. For a gas boiler with 100 W electric power the UPS should have at least 300 W (with extra power up to 450-500 W).

As for the battery capacity, let's say one 50 Ah battery will be enough for 100 W power consumption for 4-5 hours of operation. To guarantee 9-10 hours of operation it is necessary to have two of these batteries, etc.

Electricity consumption of gas boilers: how much electricity a typical heating unit consumes

This table shows the autonomy hours of the gas boiler, depending on the electric consumption of the gas boiler (electric power in W), the capacity of the battery (Ah capacity) and the number of batteries simultaneously connected (one, two, three or four)

And finally, will the UPS consume the electric power for its needs? It all depends on the efficiency. If we take COP=80%, then for our 300W UPS, the consumption together with the load will be:

300W / 0,8 = 375W, where 300W  is the load and the remaining 75W is the consumption of the UPS itself.

The above calculation example is relative and is valid for simple UPS systems, namely for the moment in which the surges of the line voltage exceed a certain level  - more than 10%. When the grid is standard 220V, the UPS consumes virtually nothing.

Detailed calculations for UPS capacity, battery capacity and the extra electricity costs of installing a UPS in a heating system are best left to an electrician.

Conclusions and useful video on the subject

How to choose a gas boiler (the video has information on energy dependent boilers and their components which require electricity to work):

How much electricity does a gas boiler use (the author of the video does a wattmeter measurement):

Autonomous power supply for a gas boiler (home \"handyman\" experience):

When buying a gas boiler, put the task of reducing electricity consumption among the last places. Electricity costs are incomparably lower than the obvious advantage - savings of up to 30% of gas consumption.

The main thing in your area have no problems with sudden power outages for a long time. And there is no doubt that the automation of the boilers provides more possibilities for setting and controlling the unit during its operation.

Please leave your comments in the block below, ask questions, post photos on the subject of the article. Share how much energy your gas unit consumes during operation. It is possible that your tips on economy and rules of boiler operation will be useful for the visitors of the site.

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