Public grants and subsidies for boiler replacement in 2025

If you’re considering replacing your boiler, we’ll guide you step-by-step through the technical requirements, open calls for applications, tax compatibilities, and frequently asked questions. Because improving your home’s energy efficiency also means taking care of the planet!

Starting 1 January 2025, public subsidies for boiler replacements have undergone major changes. The new European ErP Directive (Energy-related Products) excludes boilers powered exclusively by fossil fuels such as gas, diesel, or coal. This means that traditional gas boilers —even condensing models— are no longer eligible for subsidies.

Current financial aid programmes focus on cleaner, more efficient technologies:

• Biomass or pellet boilers, which use biodegradable fuels and emit fewer emissions.
• Hybrid systems, combining a boiler with a heat pump or solar thermal energy.
• Heat pumps and aerothermal systems, which are highly efficient and emission-free.
• High-efficiency electric boilers, though only in specific cases with technical justification.

The average subsidy ranges from €300 to €3,000, depending on the system type, regional government, and applicant profile. In some cases, the subsidy can cover 40% to 60% of the total project cost.

Technical and tax requirements to qualify for subsidies

To receive funding, you must meet a set of technical, administrative, and fiscal requirements that ensure both the efficiency of the installation and the proper use of public funds.

Energy certificates, authorised installer, and property conditions

• The property must be located in the region granting the subsidy.
• Installation must be carried out by an authorised company registered under the corresponding boiler replacement plan.
• You must provide an energy efficiency certificate both before and after the project, issued by a qualified technician.
• The replaced boiler must be at least 10 years old and legally registered.

Compatibility with Personal Income Tax (IRPF) deductions for energy efficiency

Regional subsidies may be compatible with national personal tax deductions for energy efficiency, as established under Royal Decree-Law 19/2021. However, keep in mind that:

• The subsidy amount reduces the deductible base in your tax return.
• The grant must be declared as taxable income in your tax statement.
• To apply the deduction, the energy improvement must be measurable (either a reduction in energy consumption or an improved energy rating).

Required documentation and application process

Although the process varies by region, the general documentation includes:

• A detailed invoice including VAT and a technical description of the equipment.
• Installation certificate issued by an authorised installer.
• Registered energy certificate from the relevant regional authority.
• Responsible declaration confirming the accuracy of the data provided.
• Proof of payment via bank transfer (cash payments are not accepted).

Applications are typically submitted online through the regional government’s website and must be filed within the official call period.

Regional subsidies and open calls for 2025

Boiler replacement subsidies are managed individually by each regional government, which means that eligibility requirements, deadlines, and amounts can vary significantly. Here are some of the most relevant programmes for 2025:

Madrid

The Plan Cambia 360 programme offers subsidies of up to €500 for biomass boilers or hybrid systems. Applications are open until 30 November 2025. An energy certificate and an installer company registered under the regional plan are required.

Castilla y León

Grants of up to €600 per household are available for replacing boilers over 10 years old with renewable systems. The call remains open until funds are exhausted. Applicants must register the installation and provide full technical documentation.

Valencia

The Programa Renove plan offers subsidies of up to €400 for pellet boilers or aerothermal systems. This aid is compatible with personal tax deductions and is offered annually, but with limited availability.

Galicia

Through INEGA, subsidies cover up to 60% of the total cost for biomass boilers and heat pumps. Applications are open until 15 December 2025. A technical report and energy certificate are required.

Aragon

The Plan Renove de Calderas Centralizadas (centralised boiler replacement plan) offers €1 per kW for each replaced boiler in multi-family residential buildings. Applicants must provide a technical report and installation registration.

Compatibility between subsidies, grants, and tax deductions

It’s essential to understand how subsidies are declared on your tax return and how they affect your deductions:

• All grants received must be declared as taxable income in the appropriate section of the personal income tax form.
• The deductible base for energy efficiency is reduced by the amount of the subsidy.
• You cannot apply two deductions on the same expense (e.g., both regional and national deductions without prior adjustment).

Here’s a practical example: If you install a biomass boiler worth €3,000, receive a €1,200 regional subsidy, and apply the 40% tax deduction, you can only deduct 40% of the remaining €1,800 (the adjusted base). The result is a final deduction of €720.

It’s also recommended to keep all documentation for at least four years in case the Spanish Tax Agency requests verification.

FAQ about boiler replacement and subsidies in 2025

Can I receive a subsidy if I replace a gas boiler with another gas boiler?

No. Starting in 2025, subsidies exclude boilers that run exclusively on fossil fuels.

Is the energy efficiency certificate mandatory to apply for a subsidy?

Yes. Both before and after the installation. It must be issued and duly registered by a qualified technician.

Do subsidies need to be declared in the income tax return?

Yes, they must be declared as taxable income and will affect your deductible base.

Can I apply for grants if I’m a tenant?

Only if you have the property owner’s authorisation and you directly cover the investment.

What happens if the installation is completed after the application deadline?

You won’t be eligible for the subsidy, even if you meet all technical requirements. It’s essential to respect the official application deadlines.