With the UK targeting net-zero carbon emissions by 2050, homeowners are evaluating heating options like air source heat pumps (ASHPs) and gas central heating, especially with potential hydrogen blending in the gas supply. For most UK homes in 2025, gas boilers remain far more cost-effective, but alternatives exist. This blog compares ASHPs and gas boilers and explores other heating options to help you choose.

1. How They Work

Air Source Heat Pumps

ASHPs extract heat from outdoor air, using electricity to transfer it to radiators, underfloor systems, or air vents. They’re efficient but need well-insulated homes.

Gas Central Heating

Gas boilers burn natural gas to heat water for radiators or underfloor systems. Trials for blending up to 20% hydrogen or using 100% hydrogen with hydrogen-ready boilers are underway.

Key Difference: ASHPs use electricity and ambient air; gas boilers rely on fossil fuels, potentially supplemented by hydrogen.

2. Energy Efficiency

Air Source Heat Pumps

ASHPs achieve a Coefficient of Performance (COP) of 2.5–4, delivering 2.5–4 units of heat per unit of electricity. Efficiency excels in insulated homes but dips in extreme cold.

Gas Central Heating

Condensing gas boilers are 90–94% efficient. Hydrogen blending may slightly reduce efficiency due to lower energy density, but hydrogen-ready boilers maintain performance.

Winner: ASHPs are more efficient, leveraging renewable heat.

3. Running Costs

Air Source Heat Pumps

ASHPs cost £800–£1,200 annually (at 24p/kWh for electricity in 2025). The Boiler Upgrade Scheme (£7,500 grants) helps with installation but not running costs.

Gas Central Heating

Gas boilers cost £600–£900 per year at 6p/kWh. Hydrogen blending could slightly raise prices, but full hydrogen system costs are unclear.

Winner: Gas boilers are far cheaper to run, making them the cost-effective choice for most UK homes.

4. Installation Costs

Air Source Heat Pumps

ASHP installation costs £8,000–£18,000, including system and home upgrades. Grants reduce this cost.

Gas Central Heating

A new gas boiler costs £2,500–£5,000, with hydrogen-ready models at £3,000–£6,000. Hydrogen blends need minimal changes, but full hydrogen may require pipework upgrades.

Winner: Gas boilers are significantly cheaper to install.

5. Environmental Impact

Air Source Heat Pumps

ASHPs produce no direct emissions and use increasingly renewable electricity (over 50% in 2024), cutting carbon footprints by up to 50% compared to gas.

Gas Central Heating

Gas boilers emit 2.5–3 kg of CO2 per kWh. A 20% hydrogen blend slightly reduces emissions, but most gas is fossil-based. Full hydrogen could be low-carbon with green electrolysis, which isn’t yet widespread.

Winner: ASHPs are greener, but hydrogen may improve gas boilers’ sustainability.

6. Suitability for UK Homes

Air Source Heat Pumps

ASHPs work best in well-insulated homes with modern radiators or underfloor heating. Older homes need upgrades, and ASHPs require outdoor space and can be noisy (40–60 dB).

Gas Central Heating

Gas boilers suit most UK homes, including older properties. Hydrogen-ready boilers are equally versatile, with blends requiring no changes.

Winner: Gas boilers are more adaptable for typical UK homes.

7. Maintenance and Lifespan

Air Source Heat Pumps

ASHPs need annual servicing (£100–£200) and last 15–20 years, with minimal maintenance.

Gas Central Heating

Gas boilers require servicing (£80–£150) and last 10–15 years. Hydrogen-ready boilers have similar needs.

Winner: ASHPs last longer, but maintenance costs are similar.

8. Future-Proofing

Proposed bans on new gas boiler installations in new homes (set for 2025) and replacements (targeted for 2035) have been delayed multiple times, making a full ban unlikely soon. If enforced, significant government grants would likely offset the high cost of switching to alternatives like ASHPs, as expecting homeowners to pay £8,000–£18,000 upfront is unrealistic. Hydrogen trials could extend gas boilers’ viability, but hydrogen infrastructure is uncertain. ASHPs align with electrification but are less cost-effective now.

Winner: ASHP and Gas boilers win this one! ASHP are a great option if you’ve got a well insulated home and the money to invest, however if you haven’t got money burning a hole in your pocket…. Boilers are a solid choice as they aren’t going anywhere anytime soon, with grants likely for any future transitions to alternative heating.

9. Other Heating Alternatives

Beyond ASHPs and gas boilers, consider these options:

• Ground Source Heat Pumps (GSHPs): Extract heat from the ground, offering higher efficiency (COP 3–5) but costing £14,000–£30,000 to install. Ideal for homes with large gardens but less practical for urban settings.
• Biomass Boilers: Burn wood pellets or logs, with lower emissions than gas but higher than ASHPs. Installation costs £7,000–£20,000, and fuel supply can be inconvenient.
• Electric Boilers: Run on electricity, compact, and emission-free at point of use, but running costs are high (£1,000–£1,500/year) due to electricity prices.
• Solar Thermal Systems: Use solar panels to heat water, supplementing other systems. Installation costs £3,000–£7,000, but they’re less effective in winter and require backup heating.

These alternatives suit specific homes but often have higher costs or practical limitations compared to gas boilers or ASHPs.

Conclusion: Which Should You Choose?

• Choose an Air Source Heat Pump if: You’re eco-conscious, have an insulated home, and can afford the upfront cost with grants. ASHPs are greener and align with long-term trends.
• Choose Gas Central Heating if: You want the most cost-effective option, as gas boilers are cheaper to install and run for most UK homes. Hydrogen-ready boilers offer flexibility.
• Consider Alternatives if: You have specific needs (e.g., large land for GSHPs or access to biomass fuel), but these are less common.

For most UK homeowners in 2025, sticking with a gas boiler is far more cost-effective. Repeated boiler ban delays suggest they’ll remain viable, and if banned, generous grants will likely make switching to ASHPs or other systems affordable. Consider your budget, home, hydrogen’s potential, and alternative options before deciding.

Happy heating, and here’s to a warm, cost-effective, and eco-friendly future for your home! – Rosoman Plumbing & Heating
https://www.rosoman.co.uk