Choosing a heating system for a Spanish home

Key rules

• Trade-off: The cheapest system to install is usually the dearest to run, so weigh both before you buy.
• Electric radiators: They cost least to fit but most to run, because electricity costs several times more per kWh than gas.
• Quotes: Get several written quotes and check VAT, flue work and subsidies are included.
• Fuel supply: Check whether piped gas reaches your street before planning a gas boiler.

Fuel prices and install costs change often and vary by region, so check current tariffs and get local quotes before you decide.

The short answer

The systems that are cheapest to install are usually the dearest to run, and the other way round. Electric radiators cost least to fit and most to run. Aerotermia costs most to fit and least to run. Your choice should fit your region, your building and the fuel you can actually get.

Install cost versus running cost

Rough running-cost order, cheapest first: heat pump, firewood or pellets, natural gas, butane, then electric radiators. Costs depend on your tariff, current fuel prices and your home, so treat this as a guide.

Why running costs differ

What you pay per unit of heat depends on the fuel price and how efficiently the system turns it into heat.

• Electric radiators turn all the electricity into heat, but electricity costs several times more per kWh than gas. They are the dearest to run.
• Splits and aerotermia are heat pumps. They move heat from outside instead of making it. They deliver roughly 3 to 4 units of heat per unit of electricity, so they cost about a third of electric radiators.
• Gas boilers: condensing models are about 90 to 98 percent efficient. Older non-condensing boilers are about 75 to 90 percent.
• Butane comes in 12.5 kg cylinders at a government-set price that is revised every few months. It is typically dearer than piped gas.
• Pellets are about 85 to 93 percent efficient and wood stoves about 65 to 80 percent. Both are usually cheap per unit of heat when bought in bulk. Open fireplaces manage only 10 to 30 percent, so do not rely on one for heat.

Installation: what to check

Install cost depends on home size, what is already in place and the installer.

• Splits are often installed for both heating and cooling, which helps in hot summers.
• Gas boilers need a connection and pipework. Check whether your street has piped gas before you count on one.
• Aerotermia needs an outdoor unit, a buffer tank and often new emitters. It pays back best in a home you will stay in for years and that is well insulated.
• Pellet and wood stoves need a flue and space to store fuel.

Get several written quotes (presupuestos). Check each one for VAT, flue work and any subsidies.

Fit the choice to your situation

• Region: Mild coastal areas often manage with splits or a few radiators. Cold inland areas, with long winters, reward a more efficient system.
• Building: In a rented flat you can rarely change pipework or flues, so portable or split solutions are often all you can do. In a house you own, aerotermia or a boiler is more realistic.
• Fuel availability: No piped gas means choosing between electricity, butane, pellets or wood. Pellets and firewood prices vary by region and season.
• Canaries, Ceuta and Melilla: Energy pricing arrangements differ from the mainland, so check locally.

Electricity tariffs matter

Electricity is billed per kWh on the regulated PVPC tariff, which changes hourly, or on a fixed free-market tariff. A power charge and taxes are added. If you heat with electricity, compare tariffs. Gas has its own regulated TUR tariff plus a fixed charge.

The FAQ below answers common questions on running cost, radiators, aerotermia and butane.

Frequently asked questions

Which heating system is cheapest to run per unit of heat?

A heat pump is usually the cheapest to run, followed by firewood or pellets, then natural gas, then butane, with electric radiators the most expensive. A heat pump turns 1 unit of electricity into roughly 3 to 4 units of heat, so it costs about a third of resistive electric heat. Pellets and firewood are cheapest when you buy them in bulk.

If electric radiators are the cheapest to install, why not just use them?

Electric radiators cost little to install because they need no pipework, but they are dear to run. They give 1 unit of heat for each unit of electricity, and electricity costs several times more per kWh than gas. They suit a rarely used room or a short stay, not a main home heated every day.

Is aerotermia worth the higher installation cost?

Aerotermia can be worth it if you will stay for years, because it is the most expensive to install but cheap to run. It needs an outdoor unit, a buffer tank and often new emitters. Ask for several written quotes (presupuestos) and check that VAT, flue work and any subsidies are listed.

Is butane a good alternative if my home has no piped gas?

Butane works as a fallback, but it often costs close to electric heat per unit of useful heat. A butane heater is about 75 to 85% efficient, and cylinders weigh 12.5 kg with a government-set price revised every few months. Compare it with a split or pellet stove before you commit.