Gas boilers are on borrowed time in the UK, with the government gunning for net zero by 2050. That means more homeowners are eyeing greener alternatives - and two front-runners are electric boilers and heat pumps.
Both ditch fossil fuels, both promise lower emissions, but they’re built for different types of homes. What works in a compact London flat might flop in a draughty countryside cottage.
In this guide, we’ll compare costs, efficiency, installation needs, space demands, and carbon footprint - so you can make the smart, future-proof choice for your home.
Let’s break it down…
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🔑 Key Takeaways:
Electric boilers are cheaper and simpler to install, perfect for flats or smaller homes.
Heat pumps cost more upfront but slash running costs with their superior efficiency.
Heat pumps need outdoor space and good insulation to perform at their best.
Both are low-carbon, but heat pumps typically have a smaller carbon footprint over time.
Your home’s size, insulation, and heating needs will steer you towards the right choice.
[1] How They Work (Without the Jargon)
Before we get into costs and carbon savings, it helps to understand how these systems actually heat your home.
Here’s the quick and clear version:
🔌 Electric Boilers
Think of an electric boiler as a giant kettle. It uses an internal heating element to warm water on demand - no flames, no flue, no gas.
The hot water then flows through your radiators and taps, just like a traditional boiler.
They’re simple, quiet, and compact - and often work with your existing pipework and radiators, making them an easy switch for many homes.
🌬️ Heat Pumps
Heat pumps are a bit more clever. Instead of generating heat, they move it.
An air source heat pump pulls warmth from the outside air (yes, even when it’s cold), compresses it using a refrigerant cycle, and upgrades that heat to warm your home via radiators or underfloor heating.
Ground source models do the same, but draw heat from pipes buried in your garden. They’re impressively efficient - but they need the right setup to perform at their best.
[2] Installation Costs and Hassle Factor
Let’s be honest, cost and disruption are top of mind when switching heating systems.
Here’s how electric boilers and heat pumps compare:
💷 Electric Boilers: Simple & Cost-Effective
Electric boilers are the budget-friendly pick for installation. Expect to pay around £2,000 to £4,000, including the unit and labour.
They’re usually a straight swap, especially if you’re ditching an old gas boiler.
No need for external units, flues, or major pipework changes. That keeps install times short and disruption low.
For flats, terraces, and space‑tight homes, electric boilers are a practical, low‑disruption option.
They’re compatible with existing pipework, don’t require external units or flues, and fit neatly into compact spaces - ideal for homes already wired for electric heating.
💸 Heat Pumps: Pricier But Grant-Backed
Heat pumps come with a steeper price tag. An air source heat pump typically costs £7,000 to £13,000, while ground source systems can hit £10,000 to £20,000.
The total depends on your home’s size, insulation levels, and whether upgrades (like a hot water cylinder or larger radiators) are needed.
Installation is more involved, often requiring an external unit, new pipework, and sometimes energy efficiency improvements to get the best results.
That can be trickier in small urban homes, but rural or detached properties tend to adapt more easily.
💡 The good news? The Boiler Upgrade Scheme (BUS) offers £7,500 grants for eligible air or ground source heat pump installs - a serious helping hand. Unfortunately, no grants currently exist for electric boilers.
🏆 Verdict:
Electric boilers win on price and simplicity, especially in urban or compact homes.
Heat pumps cost more upfront, but grants + long-term savings can tip the balance - particularly for well-insulated, spacious properties.
[3] Running Costs & Efficiency: What You’ll Pay to Keep Warm
Upfront cost is one thing - but what really stings (or saves) is the long-term running bill.
Let’s crunch the numbers using Ofgem’s 2025 electricity price cap: 22.36p per kWh.
🔌 Electric Boilers: Efficient, But Pricey to Run
Electric boilers are nearly 100% efficient, meaning every unit of electricity becomes heat. No flue losses, no wasted gas - just pure electric conversion.
Sounds ideal, right? But here’s the catch: electricity is expensive.
If your home needs around 12,000 kWh of heat per year (typical for a medium semi), that’s £2,683 annually at today’s rates.
You can cut costs slightly using a time-of-use tariff (like Economy 7) to heat water off-peak - but it’s still a hefty yearly bill.
🌡️ Heat Pumps: Lower Bills, Higher Expectations
Heat pumps don’t just convert electricity - they multiply it.
Thanks to a Coefficient of Performance (COP) of around 3, you get three units of heat for every one unit of electricity.
To meet that same 12,000 kWh heat demand, a heat pump only needs around 4,000 kWh, costing just £894 per year. That’s nearly a third the cost of an electric boiler.
The trade-off? Heat pumps need the right conditions to perform:
Solid insulation
Low-temperature heating systems (like underfloor or oversized rads)
Poor insulation or high heat loss? Your heat pump’s efficiency - and savings - will take a hit.
That’s why the Energy Saving Trust recommends a heat loss survey before installing one.
🏆 Verdict:
Electric boilers: Easier to install, but come with higher running costs.
Heat pumps: Need a bit more setup, but can slash your bills - especially in a well-insulated home.
[4] Space & Practicality: Will It Fit Your Home?
Your home’s layout isn’t just a backdrop - it can be the dealbreaker.
Let’s look at how each option fits into real-world spaces:
🧱 Electric Boilers: Compact & Fuss-Free
Electric boilers are small, quiet, and easy to tuck away. Most are wall-mounted and compact enough to hide in a cupboard or utility room.
No flue, no outdoor unit, no ventilation faff - just plug in and go.
This makes them a top choice for:
Flats
Terraced homes
City properties with limited space
They’re also quieter than gas boilers, since there’s no combustion or fan noise.
🌳 Heat Pumps: Space Needed, Inside and Out
Air source heat pumps need an outdoor unit, about the size of a washing machine. It must sit at least 1 metre from any wall or fence and have good airflow.
Indoors, you’ll often need space for:
A hot water cylinder
Possibly larger radiators for lower-temp heating
Got a garden or driveway? Great. Live in a high-rise or narrow terrace with no outside access? It might be a no-go.
Ground source heat pumps are even more demanding - you’ll need land for underground pipes or boreholes, which rules out most urban homes.
Because heat pumps run at lower flow temperatures (35–55 °C) compared to boilers, your home must be well-insulated to stay toasty.
The Energy Saving Trust recommends a heat loss survey before installing.
🏆 Verdict:
Electric boilers: The easy winner for space-saving and simplicity - ideal for tight or urban homes.
Heat pumps: Need outdoor space and a home that’s built or upgraded for low-temp heating.
[5] Carbon Impact & Green Credentials
Both electric boilers and heat pumps leave gas boilers in the dust when it comes to emissions - but one’s clearly greener.
🌿 Electric Boilers: Zero Emissions at Home, But…
Electric boilers produce no emissions at the point of use - no flames, no fumes, no problem.
But their carbon footprint depends on how the UK generates electricity. In 2025, the grid’s average carbon intensity is around 0.18 kg CO₂ per kWh (GOV.UK), thanks to a growing share of renewables.
For our 12,000 kWh annual heating example, that’s roughly 2,160 kg of CO₂ per year.
As the grid keeps decarbonising, that figure will fall - but the high energy use of electric boilers keeps their emissions on the higher side for now.
🌍 Heat Pumps: The Clear Green Winner
Because heat pumps use far less electricity (thanks to their 3:1 efficiency), they produce around 720 kg of CO₂ for the same 12,000 kWh of heat - a third of the electric boiler’s total.
And as more wind, solar, and nuclear power come online, that carbon footprint will shrink even further.
If cutting emissions is your top priority, heat pumps are the front-runner.
🏆 Verdict:
Electric boilers: Still a low-carbon choice, but less efficient = higher emissions overall.
Heat pumps: Best for the planet, especially as the UK grid gets greener.
[6] Which One’s Right for You?
Here’s a quick-fire guide to help you decide based on your home, budget, and priorities:
🔌 Choose an Electric Boiler if:
You live in a flat, terrace, or small urban home with limited space
You want low upfront costs and minimal disruption
Your home has poor insulation or high heat loss
You need a fast, easy install with no outdoor unit
🌬️ Choose a Heat Pump if:
You have a well-insulated home with low heat loss (get a heat loss survey!)
You’ve got outdoor space for the unit and can access the £7,500 BUS grant
You’re focused on long-term savings and cutting carbon
You’re upgrading to underfloor heating or oversized radiators
🏡 Off-Grid or Rural?
Heat pumps are ideal if you’ve got space and the budget - especially with government support.
Electric boilers make a solid fallback if you’re tight on space or upfront funds.
Next Steps For Your Heat Pump Journey:
When planning to install a heat pump for your home, there are several important factors to consider. Make sure to refer to the following guides to help you make informed decisions:
To dive deeper into these topics, head over to our advice section or check out our YouTube channel to learn more.
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