With the rising energy costs and growing environmental concerns, many property owners find themselves having a decision to make when it comes to heating their homes. Weighing up traditional gas boilers vs innovative heat pump technology.

It’s not an easy decision to make, but with our extensive experience installing both heating systems, we’ve helped guide countless homeowners, landlords, and facility managers to make the right decision for them. 

In this guide we’ll compare both heat pumps and gas boilers to help you make an informed decision about which best suits your needs.

Heat Pumps vs Gas Boilers, What’s The Difference?

Heat pumps don’t generate heat, they move it. They extract thermal energy from outside sources (air, ground, or water) and transfer it into your home. Air source heat pumps then use electricity to power a compressor that circulates refrigerant, absorbing ambient heat from outside air before distributing it throughout your home.

Gas boilers work through combustion. Natural gas burns in a sealed chamber, creating hot gases that pass through a heat exchanger. Water circulating around this exchanger absorbs the heat before being pumped through your radiators. Modern condensing boilers extract additional heat from waste gases, improving efficiency.

The fundamental difference: 

Heat pumps move heat using electricity and can provide both heating and cooling, while gas boilers generate heat through combustion, require a gas supply, and only provide heating.

Initial Installation Costs Compared

The cost difference between these systems is substantial. Gas boilers typically cost £1,000-£3,500 installed, with standard combi boilers at the lower end and premium system boilers with hot water cylinders at the higher end.

Heat pumps represent a significantly larger investment: air source heat pumps range from £7,000-£13,000 installed, while ground source systems can cost £14,000-£25,000. Heat pump installations often require additional home improvements like upgraded insulation or larger radiators, while gas boiler replacements typically work with existing infrastructure.

Running Costs and Efficiency Analysis

Gas boilers achieve efficiency ratings of 92-94%, converting that proportion of gas energy into usable heat. Heat pumps are much more efficient, delivering efficiency ratings of 300-400% (COP – Coefficient Of Performance, of 3-4) by moving rather than generating heat. For every unit of electricity consumed, they produce 3-4 units of heat energy.

Despite this efficiency advantage, running cost comparisons are complex. With current UK energy prices (gas at 7p/kWh vs electricity at 28p/kWh), heat pumps’ running costs can be similar to gas boilers, depending on your property and usage patterns. Heat pump performance varies seasonally, with peak efficiency in milder weather and reduced performance during extremely cold periods.

Which Are Better For The Environment?

Gas boilers produce carbon emissions through combustion, and a typical household gas boiler emits approximately 2.2 tonnes of CO2 annually. Heat pumps produce zero direct emissions, with their environmental impact coming solely from the electricity they consume. 

When paired with solar panels or green electricity tariffs, heat pumps can operate with minimal carbon impact, future-proofing against increasingly stringent environmental regulations and in line with the Government’s strategy to be net zero by 2050.

Space Requirements and Home Suitability

Gas boilers are compact wall-mounted units (70-90cm high, 45-60cm wide) requiring minimal space in kitchens, utility rooms, or cupboards. Heat pumps need more space. Air source heat pumps require an external unit with adequate airflow plus internal controls and often a hot water cylinder. Ground source heat pumps demand either garden space for horizontal loops or access for vertical boreholes.

Insulation quality is crucial for heat pumps, which operate most efficiently in well-insulated properties as they deliver heat at lower temperatures over longer periods.

Lifespan and Maintenance Considerations

Gas boilers typically last 10-15 years and require annual safety inspections by Gas Safe engineers. Heat pumps generally offer longer lifespans of 15-20 years, with ground loops potentially lasting 50+ years. Their maintenance requirements are less intensive, with fewer mechanical failures due to fewer moving parts, though specialised repairs can be costlier due to the technology’s relative novelty.

Government Incentives and Grants

The UK government’s Boiler Upgrade Scheme offers £7,500 grants toward heat pump installation costs, substantially reducing the price gap. There are also regional grant programs like the Warm Homes Programme Wales (which offers up to £5,000 towards installation) and the Home Energy Scotland Grant (which offers up to £7,500). Lastly, the ECO4 scheme provides up to 100% coverage for low-income and vulnerable households

Future policy directions include potential gas boiler bans in new builds from 2025, with wider restrictions possibly following. Commercial properties and landlords may qualify for additional incentives like 0% VAT on heat pump installations up until March 2027 and enhanced capital allowances for energy-efficient technologies.

Which Option is Best for Your Situation?

Heat pumps are typically best suited for:

• Well-insulated properties with sufficient installation space

• Environmentally conscious homeowners prioritising carbon reduction

• New builds or properties undergoing major renovation

• Rural properties off the gas grid

• Long-term occupancy where lower running costs provide return on investment

Gas boilers are well-placed for:

• Older properties with limited insulation or space constraints

• Homes requiring high-temperature heating

• Budget-conscious homeowners with limited upfront capital

• Properties where minimal installation disruption is essential

• Situations requiring rapid heating response

Choosing between a heat pump and gas boiler is a decision that balances financial, practical, and environmental considerations. 

At Custom Heat we’re here to help, our expert team provides comprehensive assessments to help you make the right choice for your specific circumstances so don’t hesitate to get in contact for a free consultation.