Heat Pump vs Gas Boiler — Which Is Right for Your Home?
With energy bills climbing and environmental concerns growing, many UK homeowners are wondering whether now is the right time to ditch their gas boiler for a heat pump. It's a question that crops up regularly — whether you're facing a boiler breakdown, planning ahead, or simply curious about what modern heating technology can offer. The decision isn't straightforward because it depends on your home's condition, your budget, and your long-term plans. This guide breaks down the real differences between heat pumps and gas boilers, helps you assess whether your home is suitable, and walks you through the costs and savings involved. By the end, you'll have a clear picture of which option makes sense for your situation — and whether it's worth calling in a qualified installer to explore further.
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Heat pumps and gas boilers heat homes differently: a boiler burns gas to generate heat at 60–80°C, while a heat pump moves heat from the outdoor air into your home at 35–55°C using electricity. Heat pumps produce 2.5–4 units of heat per unit of electricity — making them more efficient than boilers when correctly installed.
Is your home suitable? Heat pumps work best in well-insulated homes with low heat loss. A rough rule of thumb: if your home has solid walls with no insulation and single glazing, insulate first. Heat pumps work in most UK homes that have loft insulation and double glazing — they do not require underfloor heating, though larger radiators may help.
Cost comparison: gas boiler replacement costs £1,500–£3,500. An air source heat pump costs £8,000–£18,000 installed. The UK government's Boiler Upgrade Scheme (BUS) provides a £7,500 grant toward the cost of an air source heat pump — check if you are eligible at gov.uk/boiler-upgrade-scheme.
Running costs: heat pumps use electricity (more expensive per unit than gas), but use far less energy to produce the same heat. In a well-optimised system on a competitive electricity tariff, running costs can be comparable to a gas boiler — and will improve as electricity gets cleaner and the gas-to-electricity price ratio narrows.
The installation must be carried out by an MCS-certified heat pump installer to qualify for the BUS grant and any associated benefits. Find a certified installer at mcscertified.com.
There is no requirement to switch — gas boilers remain legal and will continue to be serviced and repaired. The government has set a target to phase out new gas boiler installations by 2035, though existing boilers can remain in service beyond this date.
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Frequently asked questions
Will a heat pump work in my older house with solid walls?
Heat pumps can work in solid-walled homes, but performance depends heavily on insulation levels. If your walls are uninsulated with single glazing, adding insulation first will improve efficiency dramatically and make the heat pump far more cost-effective in the long run.
Do I need to replace my radiators when installing a heat pump?
Not necessarily — heat pumps can work with standard radiators in most UK homes. However, larger radiators or additional ones can improve efficiency since heat pumps deliver warmth at lower temperatures than gas boilers, so more surface area helps distribute heat better throughout your rooms.
What's the real difference in running costs between a heat pump and a gas boiler?
Whilst electricity costs more per unit than gas, heat pumps use considerably less energy to produce the same warmth — typically 2.5–4 units of heat per unit of electricity. In a well-insulated home on a competitive electricity tariff, running costs can be comparable to gas, and the gap continues to narrow as electricity becomes cleaner and cheaper.
Is the £7,500 Boiler Upgrade Scheme grant guaranteed if I install a heat pump?
The grant is available to eligible households, but you must use an MCS-certified installer for the work to qualify. Check your eligibility on the government website before committing — criteria include property type and current heating system — and get a quote from a certified installer to confirm you can access the scheme.
What happens if I don't switch from my gas boiler — will it become illegal?
Your existing gas boiler remains fully legal and can be serviced and repaired for many years. The government's 2035 phase-out target applies only to new boiler installations, not replacements of existing systems, so there's no forced deadline to switch if you prefer to stay with gas.
How long does a heat pump installation take?
A typical air source heat pump installation usually takes 2–5 days depending on your home's layout, pipework arrangements, and any preparatory work needed. An MCS-certified installer will assess your property during a survey and give you a realistic timescale before work begins.