How much does it cost to install a boiler?

• Natural gas boiler: these types of boiler run on piped natural gas. They range in price from €600, depending on the technology used (which we will detail below).
  
• Propane gas boiler: these types of boiler use piped natural gas or gas stored in tanks. As above, there are also different types.
  
• Oil boiler: these types of boiler use oil, which needs to be stored in a tank. Oil boilers start from €1,800.
  
• Electric boilers: these types of boiler run on electricity; they can either be mixed (heating and DHW) or heat-only. Electric boilers range in price from €100 to €800.
  
• Wood pellet boilers: these boilers use fuels of plant origin, such as wood, woodchips, olive pits, almond shells, etc. Among these, pellet boilers stand out. They only use pellets—cylinders made with shavings, sawdust and chips formed from compressed wood—as fuel. Pellet boilers range in price from €2,100 to €3,200. Although initial costs are higher than for other types of boilers, bear in mind that some Autonomous Communities and the IDAE (Institute for Diversification and Saving of Energy) offer grants to people to buy this type of boiler, as part of its policy of promoting energy efficiency and heating systems that are more respectful of the environment.

As well as being classified depending on the type of fuel used, boilers differ in terms of what technology they are fitted with:

• Atmospheric boilers: the installation of this type of boiler is currently prohibited. They get the air they need for combustion directly from the room they are installed in.
  

• Room-sealed boilers: gas combustion takes place inside in order to produce domestic hot water and heating in an isolated and closed chamber. They absorb outside air and expel it through a pipe or extractor. By law, they can only be installed in isolated single-family homes or in blocks of flats where gases are extracted through the roof. Prices start at €600.

• Low NOx gas boilers: these types of boiler are also room-sealed and have a flame pre-cooling system, so gas combustion does not take place at such high temperatures. They are less polluting and can be installed in multi-family homes that have smoke outlets on the front. Prices start from €900.

• Condensing boilers: boilers that take advantage of the high temperature of the gases burned to continue heating water thanks to the recirculation of gases burned. They are the most efficient boilers since they save up to 30% on fuel. Bear in mind that for installation, a discharge pipe is required to remove the condensed water. Condensing boilers range between €900 and €2,300

What do I need to know to calculate the price of a boiler?

After you have chosen what kind of boiler you want in terms of fuel and technology, you need to calculate the power required. In this calculation, you need to take into account the geographical area where the house is located (cold or warm climate), its features and how many square metres it has (whether it is a flat located in a residential building, or an isolated private house with several floors, etc.), and the number of people living there.

A quick way to estimate how much power a boiler will need for heating is to multiply the surface area of your home by 100 W. Therefore, for a flat of 100 m2, a power of 10 kW would be required (1kW = 1000 W). To calculate the power required for domestic hot water (DHW), the formula is a little more complicated, but the most commonly used powers in homes tend to range between 24 and 35 kW. For example, a 25 kW condensing boiler would be enough to heat a 200 m² house and provide instant hot water for a bathroom and a toilet.

The other factor that will determine how much it will cost to install a new boiler is where it will be installed and whether or not works need to be carried out. Bear in mind that gas boilers are wall-mounted boilers, which have to be installed on the wall, while oil or biomass boilers are floor-standing boilers, and require enough space for installation.

In some cases, companies specialising in the installation of air conditioning, gas and heating systems offer a free basic installation, which includes dismantling the old boiler and installing the new one using the existing outlets. However, if any masonry or plumbing works have to be performed, a separate quote will be provided. Therefore, the distance between the place the boiler will be located and the front of the building, whether or not the front of the building has to be drilled to install the smoke outlet, additional length for smoke outlets, gas, heating and DHW connections, discharge pipe length (for condensing boilers), whether the boiler needs to be relocated, whether a plug needs to be installed or a new gas system needs to be installed, etc., are just some of the factors influencing the final quote for the installation of a new boiler.

Finally, in your calculation for upgrading your boiler, do not forget the cost of the gas installation certificate. This is a certificate that certifies that the gas supply installation (whether natural or propane) is safe and complies with regulations. The cost of the gas installation certificate will depend on the type of installation, the property and the company installing it, but it generally ranges between €60 and €150.