How to choose a boiler?

  Before you decide on a particular boiler, you need to clarify what you want to heat, what heating comfort you imagine, what financial resources you have, what the heated object will allow, and whether you have enough space for fuel storage.

What to heat?

There are basically four types of fuel:

  • Wood
  • Coal
  • Electricity
  • Gas

 Raw wood is the cheapest fuel for heating buildings today. But it must be said that it is one of the less comfortable way of heating, because its acquisition and handling requires your energy and time, already prepared wood and money. In addition, high-quality wood has to be dried for several years. Most of the fuel wood in the Czech Republic has a high water content (around 20%).

On the other hand, the most elegant but also the most expensive way is electric heating. The electricity bill for a larger family house can climb up to 80,000 crowns per year. But electricity heating is suitable for low-energy buildings and well-insulated houses, older homes can significantly increase the price of electricity heating. TIP: Some energy distributors offer a cheaper 20-hour tariff, known as the D45d, if you apply for it and learn to use all appliances during a low tariff, your electricity costs may drop by as much as 50%.

  Gas heating is a good compromise. The heating season will cost you around 35,000 crowns. The future is in condensing gas boilers, because with this technology, heating costs have dropped significantly and efficiency has increased too.


What heating comfort do you want?

 The most important feature of the boiler is its ability to control the heating process, ie control over the supply of fuel and combustion air to the fireplace. The more the boiler itself is able to optimally control this process without operator intervention, the higher the prerequisite for better combustion. Gas and electric boilers are more comfortable but also more demanding on operating costs. In the case of solid fuel boilers, the most elegant option is an automatic boiler. Its purchase price is three times higher than an ordinary solid fuel boiler, but can save more than 20% of fuel costs annually.


Boiler price

If you are thinking about buying a boiler, it is necessary to bear in mind that the individual price ranges correspond to its lifetime, equipment and especially performance.

Boilers around 30.000 CZK

For this price you can buy any type of boiler (electric, gas, solid fuel boilers, and some condensing boilers). For solid fuel boilers, you usually get an output of around 30 kW, electric boilers have an output of 45 kW and gas boilers have a storage tank of up to 55 liters.

Boilers from 35.000 CZK to 70.000 CZK

Boilers in this range already have interesting technologies and special programs. Within this price range, you will purchase steel or cast iron solid fuel boilers with their own wood or pellet hopper. The boiler output is around 75 kW. Electric boilers in this price range are mostly free-standing (stationary) and gas boilers are mostly condensing.

Boilers from 70.000 CZK to 90.000 CZK

Boilers at this price have a really high output and are able to heat large spaces, including commercial ones. Solid fuel boilers of this value are usually very simple to operate and also self-serviced.


What type of boiler you should buy?


The basic distribution of boilers is as follows:

  • Hanging (hanging on the wall)
  • Stationary (standing on the floor)

Before buying, it is also necessary to realize whether you want the boiler only for heating or whether you also want to heat the domestic water. In this case, the following are available on the market:

  • Boilers with instantaneous heating - they heat water that is just inside the boiler in the exchanger. This function is provided by gas boilers
  • Boilers with built-in hot water tank - boilers usually have a 50 l tank, in which the hot water is stored. This function is mainly performed by gas boilers.
  • Boiler with external storage tank - the storage tank is not part of the boiler and there is no separate electric water heater inside the tank. The external storage tank is usually a part of gas and electric boilers

It is also necessary to select the boiler performance.


How to calculate boiler performance?


 You need to calculate the required boiler performance by an expert, because for the exact calculation it is necessary to count with several parameters such as window quality, insulation level, places with heat leaks, age of the building, age of central heating and others. However, if you want to see the approximate output yourself and determine the range of boilers to choose from, you can try a simple procedure:

  • First it is necessary to know the living area of ​​the house (m2) or the heated space of the house (m3).
  • Furthermore, the age of the house and its possible insulation.
  • And whether the house has a new or older installation of central heating (UT) and domestic hot water (DHW).

You can check the approximate performance in the table below. Just choose the character of the building and the type of insulation and then the heated area (m2) or room area (m3). The first column then shows the power needed to increase the temperature by 30 ° C (eg from -10 ° C outside to + 20 ° C inside):


Boilers performance NEW HOUSE
Well insulated
walls without insulation
Greenhouse spaces
with insulation
 kW m3 m3 m2
 5 kW 70-150 m3 60-110 m3 35 m2
 10 kW 150-300 m3 130-220 m3 70 m2
 20 kW 320-600 m3 240-440 m3 140 m2
 30 kW 650-1000 m3 460-650 m3 210 m2
 40 kW 1050-1300 m3 650-890 m3 300 m2
 50 kW 1350-1600 m3 900-1100 m3 370 m2



The above applies only to the calculation of boiler output for heating the building. However, if you intend to use the boiler also for domestic hot water (DHW), multiply the resulting output TWICE.

More detailed calculation of boiler output can be found HERE.