What Will Replace Oil Boilers in 2025?

If you live in a rural area of the UK, chances are that your home is warmed by an oil boiler. It's been the standard for off-grid homes for decades. But times are changing.

It is discouraged to install new oil boilers in new-build houses in 2025. So what happens next? What kind of heaters will fill the void when oil boilers are no longer with us? And how do homeowners prepare for that? And can they get a new heating system installed under the Free Boiler Grant?

Let's explore!

Why the UK Is Moving Away from Oil Boilers

The main incentive for phasing out oil boilers is the UK's net-zero target – the government's target to cut carbon emissions to almost zero by 2050.

Oil boilers burn fossil fuels, releasing high volumes of carbon dioxide (CO₂). In fact, heating oil releases more CO₂ for each unit of heat than gas. And it is thus among the most carbon-intensive means of heating.

That is why the government would rather replace aging oil heating with cleaner, low-carbon technologies such as heat pumps and biomass boilers. They are cleaner and use less energy.

What Will Replace Oil Boilers in 2025?

There isn't one simple replacement – homeowners will have a range of options, depending on their property, their heating needs, and whether they are on the gas grid.

The following are the most common heating options that will replace oil boilers in the coming years.

1. Air Source Heat Pumps (ASHPs)

Air source heat pumps are already the UK's leading alternative to oil boilers.

They work by drawing heat from outside air (yes, even in winter) and using it to warm your home and hot water.

How They Work

• There is an outdoor fan unit that draws in air at the rear of your house.

• The system extracts the heat from the air and blows it into your heating system.

• It's a reverse fridge in operation – transferring heat instead of generating it.

Benefits

• Around 300–400% efficient, and they produce 3–4 units of heat for 1 unit of electricity consumed.

• Saves on heating bills up to 30–50% compared to an oil boiler (particularly when well-insulated).

• Zero emissions are produced at installation.

• You can get Free Air Source Heat Pump Grants under the scheme ECO4.

Best For

Well-insulated properties with space for an external unit (especially rural homes off the gas grid).

2. Ground Source Heat Pumps (GSHPs)

Ground source heat pumps operate similarly to air source systems but pull heat out of the ground instead of the air. Underground pipework is fitted to absorb consistent temperatures throughout the year.

Benefits

• Highly consistent and effective, even in cold weather.

• Lower long-term running costs than oil or electric heating.

• Need hardly any maintenance and can last for 25 years.

Disadvantages

• More expensive to buy upfront (usually £18,000–£25,000).

• Require sufficient amounts of land space for trenching or boreholes.

Ideal For

Larger rural houses with gardens or land – a perfect option for rural houses to replace oil boilers.

3. Biomass Boilers

Biomass boilers are another eco-friendly choice. They use wood pellets, logs, or chips instead of oil.

They still release CO₂, but it's "carbon neutral" as the fuel is from trees that have been grown sustainably and absorb carbon when growing.

Benefits

• Can be integrated into existing radiators and hot water systems.

• Less costly to run than oil, especially in rural areas.

• Covered by support under some renewable heating schemes.

Disadvantages

• Require frequent maintenance (ash removal, cleaning).

• Require a fuel storage area, so you will require room for wood pellets or logs.

Best For

Farmhouses with enough space and easy access to biomass fuel suppliers.

High-Efficiency Gas Boilers (for Domestic Properties on the Gas Grid)

If you own a property that can access mains gas, it remains a great option to replace an oil boiler with a new A-rated gas boiler under the ECO4 Free Boiler Grant.

Why?

• Gas is a cleaner burn than oil and emits around 30% less CO₂.

• They keep the heat which otherwise goes down the flue, and they are thus over 90% efficient.

• They are also cheaper to install and run than heat pumps.

The ECO4 Scheme, the Free Boiler Grant

The Free Boiler Grant is the government's ECO4 stage, or Energy Company Obligation Phase 4. It operates between 2022 and 2026.

It features energy-efficient enhancements like the free fitting of A-rated boilers, loft insulation, and even air source heat pumps for eligible homes.

Who is Eligible?

You may be eligible if:

• You are on particular benefits (e.g., Pension Credit, Universal Credit, or Housing Benefit).

• Your house has an EPC rating of lower D, E, F, or G.

• Your property is your own, or you are privately renting your home.

What You Can Receive

• Free replacement of old gas or oil boilers with new, efficient boilers.

• Installation financing for a heat pump.

• Insulation of the loft or walls for free.

So even if oil boilers are being phased out, you are not excluded. The government is helping you switch over at a reasonable cost.

How to Get a Free Boiler Grant

It is quick and easy to apply. Here is how:

1. Check Your Eligibility:

Visit a registered ECO4 installer's website and fill in a brief eligibility form.

2. Free Home Assessment:

Our expert will come to your current heating system and evaluate the EPC rating for your home.

3. Grant Approval:

Once approved, your energy supplier arranges payment for the grant to fund the installation.

4. Installation:

Your current oil boiler is replaced with a brand-new, cost-saving system — free or at substantially reduced expense.

The whole process would only take 1–2 weeks based on the rates of application and supply of installers.

The Bottom Line: The Future Is Greener

Those oil boiler days are long gone. Low-carbon heating will become the standard in the UK by 2025, fueled by air source heat pumps, biomass boilers, and low-loss gas systems.

If you're already reliant on oil heating, then the ECO4 scheme Free Boiler Grant is a simple, low-cost way to make the upgrade.

You'll gain:

• Reduced fuel bills

• Super-efficient new heating

• A warmer, cleaner home

Upgrading not only future-proofs your home but also assists the UK in taking a step towards a cleaner, greener, more sustainable future.