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Heat pumps vs gas boilers — which is better for heating your home in 2025?
That’s the question many UK homeowners are now asking, especially with rising bills and stricter climate rules. If your boiler is old or your heating is poor, now is the time to make a smart decision.
And for the 150,000 off-grid homes in the UK, a gas boiler may not even be an option. That’s where heat pumps come in.
In this guide, we’ll compare both systems side by side — costs, efficiency, lifespan, maintenance, and support available in 2025.
Heat Pumps vs Gas Boilers in 2025: How Do They Compare?
What is a Heat Pump?
It is an environmentally friendly heating system that uses external air (even when it’s cold outside) to heat your home. The most common type is an air source heat pump. It’s kind of like having an air conditioner placed in front of your house.
Instead of producing heat from the burning of fuel, a heat pump moves heat, like a refrigerator in reverse. It sucks in heat from outside air with a small amount of electricity, compresses it, and transfers it to your hot water tank, radiators, or underfloor heating. That is why heat pumps can be up to 300–400% efficient.
What’s a Gas Boiler?
A gas boiler burns natural gas to create heat for your radiators and hot water. It’s the UK’s most common heating system and has been in use for decades.
New gas boilers are now all condensing boilers, which means they’re a minimum of 90% efficient. That is a big improvement from the old-style boilers, but they are not as effective as using a heat pump.
While gas boilers heat water very quickly and are cheaper to install, they also produce carbon dioxide. They rely on fossil fuels, which are being phased out over time.
Heat Pumps vs Gas Boilers: 2025 Comparison
| Feature | Heat Pump | Gas Boiler |
|---|---|---|
| Energy Source | Electricity | Natural Gas |
| Efficiency | 300–400% efficient | ~90% efficient |
| Carbon Emissions | Zero on-site emissions; depends on grid electricity | ~215g CO₂ per kWh |
| Running Costs | Lower in well-insulated homes | Lower per kWh but less efficient overall |
| Installation Cost | £10,000–£22,000 (air source); often free via ECO4 | £1,700–£3,500 |
| Noise Level | ~42 dB (regulated by law, outdoor unit) | 40–60 dB (indoor unit) |
| Heat Output | 35–55°C (slower heating, best in insulated homes) | 60–80°C (fast and powerful) |
| Maintenance | Low | Needs annual servicing |
| Suitability for Old Homes | Needs insulation + bigger radiators or underfloor | Works well with existing radiators |
| Grant Support (ECO4) | Often 100% free for eligible homes | Free boiler available for qualifying households |
| Suitable for Off-Grid? | Yes | No |
| Lifespan | ~20–25 years | ~10–15 years |
| Best For | Long-term savings + eco-friendly heating | Quick install + short-term affordability |
Electricity vs Gas: Unit Prices in 2025
From 1 April to 30 June 2025, the UK energy regulator, Ofgem, has set the following price limits:
- Electricity: 27.03p per kWh
- Electricity standing charge: 53.80p per day
- Gas: 6.99p per kWh
- Gas standing charge: 32.67p per day
This clearly shows that electricity costs nearly four times more than gas per unit. So at first glance, it seems like running a heat pump would cost much more.
But efficiency is where it all breaks down.
- A gas boiler could lose 10–20% of the energy that it burns.
- A heat pump will produce 3 to 4 units of heat for every unit of electricity that it uses.
So even though each unit of electricity costs more, heat pumps consume less than a fraction of the units to warm the same area.
Check Eligibilty For ECO4 Scheme
Get Free Heating System Installed Today at your Property Under ECO4!
Heat Pump vs Gas Boiler: Which Is More Efficient?
Gas Boilers
New gas boilers are now at least 90% efficient, which means 90% of the gas is converted into heat. But 10% is still wasted — normally down the flue. So for every £1 you pay, you waste around 10p.
Heat Pumps
Heat pumps are much more efficient. Most air source heat pumps have an efficiency of about 300%, which means they produce 3 units of heat for each 1 unit of electricity consumed. Some types of heat ground source pumps go even higher.
Heat Pumps vs Gas Boilers: Installation Complexity Compared
Installing a Gas Boiler
It is normally fast and easy to install a gas boiler. The majority of homes within the UK already possess a gas supply, radiators, and piping.
If you are only replacing a worn-out boiler, then it will often be done in under one day. Gas engineers can be found easily, and prices tend to be lower as it is a well-known process and easy to undertake.
Installing a Heat Pump
Installing a heat pump is more time- and planning-intensive. A standard air source heat pump installation takes 2 to 3 days. You’ll also require an outdoor unit with sufficient space and airflow.
In certain houses, your radiators will require upgrading, or you’ll need additional insulation to retain the warmth. This makes it longer and more costly initially.
But under the ECO4 scheme, most homeowners would be able to have free or subsidised heat pump fitting, making the cost lower or even close to zero.
Heat Pumps vs Gas Boilers: Running Cost Comparison
Gas is less expensive per unit (6.99p/kWh) than electricity (27.03p/kWh), yet gas boilers are merely 90% efficient. Heat pumps, however, are 300-400% efficient, that is, they generate 3 to 4 units of heat for each unit of electricity.
Heating, for the most part, occurs between October and March. According to prices now, heat pump operating costs are £840 to £2,280 a year (around £70 to £190 per month), depending on your property and how well insulated it is.
Gas boilers can cost £900 to £1,400/year, plus a £119 gas standing charge. You can cut these expenses using heat pumps.
Verdict: Since there are no gas connection charges and heat pumps have improved efficiency, they are cheaper in the long term.
What the Research Says About Running Costs
Experts measure the efficiency of heat pumps using SCoP (Seasonal Coefficient of Performance). If you have an SCoP of 3, you’re receiving 3 units of heat in exchange for 1 unit of electricity.
A UK study discovered the average heat pump had an SCoP of 2.9, on a par with a modern 90% efficient gas boiler. However, some properly installed systems had SCoPs of 4, even in older houses.
If you’re upgrading from an existing, inefficient boiler, the Energy Saving Trust estimates you could save £340 a year. So, though savings will vary depending on your existing setup, heat pumps will save you more in the long run.
Carbon Footprint: Heat Pumps vs Gas Boilers
Gas Boilers
Gas boilers burn fossil fuels. A new A-rated condensing gas boiler produces approximately 215 grams of CO₂ per kWh of heat.
That’s over 1,200 kg of CO₂ per year for an average house. Though better than old boilers, it’s still a big source of carbon emissions from the home.
Heat Pumps
Heat pumps never burn anything. They move heat with electricity. That means no carbon emissions from the appliance itself.
But the electricity they use still contains some proportion of fossil fuel. Around 40% of the UK’s electricity is renewable, so there are lower emissions, and these will keep falling as the grid gets steadily greener.
Verdict: If the environment is your top priority, heat pumps are the winner. They reduce your home’s carbon footprint substantially, and in the long term, they will be even cleaner.
Gas Boilers vs Heat Pumps: Upfront Cost
Gas Boilers
A new gas boiler costs £1,700 to £3,500 to install. Most houses already have pipework in place, so there’s a speedy and affordable installation. It’s the cheaper option upfront — perfect if you don’t have grand home renovations in mind.
Heat Pumps
Air source heat pumps cost between £10,000 and £22,000 to install. Ground source comes in at up to £25,000. They are more complex to fit and will often involve replacing insulation or radiators.
Verdict: Gas boilers are cheaper to install, no question about it. But heat pumps can cost you nothing if you’re eligible for a heat pump grant.
Performance & Heat Output Compared
Gas Boilers
Gas boilers are like kettles on steroids. They warm water in a jiffy and blast it around your radiators at around 70°C.
That’s hot enough to warm even a draughty house in a flash. They’re ideal if you want instant heat on a freezing morning — no delay.
Heat Pumps
Heat pumps work differently. They heat water to a lower temperature, usually 35°C to 45°C for space heating and around 55°C for hot water. That’s not as hot as with a boiler, so they heat a room slowly.
To get the best out of them, your home needs to be well insulated, and you may need bigger radiators or underfloor heating to circulate the heat effectively.
Verdict: If your home is old, draughty, and poorly insulated, a gas boiler may be more effective without the upgrades. But if your home is new or well-insulated, a heat pump will keep you just as warm.
Heat Pump vs Gas Boilers: Which is Noisier?
Gas Boilers
Most gas boilers in the UK produce 40–60 decibels (dB) — about the same as a quiet conversation. Indoors and well-insulated, the noise is barely noticeable.
Heat Pumps
Heat pumps are restricted to 42 dB by UK planning policy (1 metre from a neighbour’s window). Quieter than most boilers, but because they are outside, it might travel further, particularly at night or in freezing weather.
Verdict: Both are reasonably quiet. Boilers might be noisier inside; heat pumps are quieter, but outside. Placing carefully keeps both within comfort.
Lifespan Comparison
As far as your heating system’s lifespan goes, heat pumps clearly have the advantage. A ground source heat pump could possibly be longer-lasting, and an air source heat pump, properly maintained, could last 20 to 25 years.
By contrast, a gas boiler will last for around 10 to 15 years before it has to be replaced. So, in 25 years, you may have to install two boilers but a single heat pump.
Is My House Suitable for a Heat Pump?
Not all homes are heat-pump suitable, but most homes can be upgraded with ease. Here is what your home needs to be heat-pump friendly:
- Good insulation: Heat pumps work best in homes that don’t lose heat quickly. Loft and wall insulation can help a lot.
- Space outside: You’ll need some room outdoors for the heat pump unit — about the size of a washing machine.
- Modern radiators or underfloor heating: Because heat pumps run at lower temperatures, larger radiators or underfloor systems can help spread the warmth better.
If you’re not certain whether your home is ready, then it’s well worth getting a free survey under the ECO4 scheme. They will inform you what needs to be done, and in most cases, they cover it by paying through the grant.
Can I Get a Grant for a Heat Pump?
Yes. If you’re on a low income or receive certain benefits, the ECO4 scheme can cover the full cost of installing an air source heat pump in your home.
The grant is funded by the UK government and delivered through big energy companies. It’s designed to help people heat their homes more efficiently and lower their bills.
To qualify, you usually need:
- A home with a poor EPC rating (usually D or below)
- No connection to mains gas
- And you or someone in your home is receiving eligible benefits
Think you might qualify? It’s free to check — and you could save thousands.
So, Which One Wins in the Long Run?
If you want:
- Fast heating
- Lower upfront cost
- And your home isn’t well-insulated
Then, a gas boiler still makes sense in the short term.
But if you’re thinking about:
- Long-term energy savings
- Lower carbon emissions
- And a warmer, future-ready home
Then a heat pump wins hands down.
The Bottom Line
If you need a quick, cheap fix: go with a gas boiler. But if you’re eligible for a grant and want lower bills, greener heating, and long-term savings, a heat pump is the smarter choice for 2025 and beyond.
FAQs
Yes, heat pumps typically produce lower carbon emissions compared to gas boilers, making them a greener choice.
Both heat pumps and gas boilers generally last between 10 to 15 years with proper maintenance.
The installation cost of a heat pump ranges from £2,400 to £19,000, while gas boilers typically cost between £500 and £3,500.
Heat pumps need servicing every 2-3 years, while gas boilers generally require annual checks.
