Heating boilers

Boilers for heating and/or DHW:

If you already know what type of boiler you need, you can click directly to see all the models available on our website. Remember that in our online store you have the option to finance your purchase of heating products.

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  Gas boilers

  Models from leading brands: Domusa, Junkers, Intergas, Saunier Duval and Ferroli.

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  Diesel boilers

  Over 90 diesel boiler models to choose from in our Domusa and Ferroli catalogue.

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  Electric

  Options to plug your boiler directly into the power grid.

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  Biomass or pellets

  Save on fuel with the biomass boiler models available.

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  Solar

  Take care of the environment and heat your home with a solar solution.

If you have any questions or need to know more, you have two options:

1. You can contact our team of experts, always ready to help you make the best choice, by clicking here.
2. Or you can keep reading—below we explain everything you need to know about boilers to make sure you choose what suits you best.

Everything you need to know about boilers:

• > What is it and how does it work?
• > Boiler consumption
• > When to replace your boiler
• > Boiler catalogue

What are boilers and how do they work?

A boiler is a heat-generating machine that uses a specific energy source to heat a fluid—generally water. The heat produced is pumped through a network of pipes to the emitters (radiators or underfloor heating) to ensure a comfortable indoor temperature.

In Spain, boilers are the most common method for home heating and for producing hot water. Technological advances have made it possible to use boilers for both heating and DHW. By combining both functions in one appliance, you save space and costs.

Types of boilers:

Thanks to technological development, boilers have improved over time and today there is a wide range available. Boilers can be classified by how they work or by the fuel they use.

Boiler types by fuel:

Depending on the fuel used to generate heat, boilers are classified as:

• Electric boilers: Generate heat using a heating element. This technology allows power regulation and improved efficiency. There is no combustion, no fuel flow, no need for tanks, and no concerns about leaks or flue gas evacuation.
• Gas boilers: The burner uses gas, which can be:
• Natural gas: Economical and eco-friendly, but it requires an installation connected to the supply network. The investment is usually recovered quickly thanks to energy savings.
• Butane gas: High calorific value, but less suitable for very cold areas. It’s supplied in cylinders, so it’s advisable to keep a spare to avoid running out.
• Propane gas: Used in very cold areas due to its calorific value. Commonly supplied in 13 or 35 litre bottles, or in bulk to fill tanks (minimum capacity around 1,000 litres).
• Biomass boilers: Use natural, more eco-friendly fuels of plant origin. The most in-demand are pellet boilers, made from forest residues and wood chips. Biomass is not a fossil fuel, so it does not generate greenhouse gases in the same way.
• Diesel boilers: Used mainly in homes without access to the gas network. They require space to store fuel, but they heat up quickly and have relatively simple maintenance.

Boiler types by operating system:

According to this classification, we find three types:

• Condensing gas boilers: Their design allows the use of heat released when water vapour in the flue gases cools down, preheating domestic hot water (DHW). This reduces energy consumption when DHW is demanded and makes the system highly efficient.
• Room-sealed boilers: The combustion chamber is airtight, minimizing accident risk because gas cannot leak into the home. Oxygen for combustion is taken from outside using a fan, and combustion gases are expelled safely.
• Open-flue (atmospheric) boilers: Have an open combustion chamber that uses indoor air. These boilers can no longer be installed.

Which boilers consume less and which are the most efficient?

Condensing gas boilers are highly efficient and can deliver energy savings of up to 30% compared to conventional boilers. They also reduce pollutant greenhouse gas emissions—carbon dioxide (CO2) and nitrogen oxides (NOx).

Their efficiency can exceed 100% when used with underfloor heating or low-temperature radiators, while standard boilers typically reach a maximum of around 90%.

This is because these systems work with the return water temperature. That way, the boiler spends most of the time condensing and recovering energy from flue gases to increase efficiency.

In addition to high efficiency and low CO2/NOx emissions, condensing boilers offer other advantages, including:

• Lower gas costs: By recovering condensation heat, these boilers can use around 25% less gas than conventional models.
• Power and temperature modulation: They operate according to demand and perform well even in very low outdoor temperatures, covering heating needs even at minimum power.
• Low noise: They run continuously without frequent stops/starts, making them very quiet.

Regarding natural gas heating installation costs, it requires building work and therefore a significant investment. However, payback is usually short due to the low supply cost and high system efficiency.

It’s also worth noting there may be grants/subsidies available to replace your heating system with natural gas.

When should you replace your boiler?

Gas boilers typically have a service life of 10 to 15 years. The Institute for the Diversification and Saving of Energy (IDAE) recommends replacing a boiler after 15 years of operation, as material wear over time negatively affects performance.

Over time, boilers tend to lose efficiency, making failures and breakdowns more likely and increasingly frequent. That is usually the main reason they are replaced, since repeated repair costs can become quite high.

Another reason to replace a boiler is a change in the heating system—e.g., switching to underfloor heating or low-temperature radiators requires a compatible boiler.