DATA-BACKED GUIDE · UPDATED JULY 2026
New boiler vs heat pump: the real installed cost
Comparing a new boiler against a heat pump on cost means looking past the sticker price of the unit and weighing the installed price after any grant, plus what each one actually costs to run. A gas boiler is usually cheaper to install and simpler to fit into an existing system, while a heat pump costs more upfront even after grant support but can cost less to run over time depending on your home's insulation and the electricity tariff you are on. The right answer depends less on the technology and more on the house it is going into.
The quick version
- A heat pump installation typically costs more upfront than a like-for-like boiler swap, even after grant support is applied.
- The Boiler Upgrade Scheme grant reduces the heat pump price but does not remove the gap entirely, and eligibility rules can change.
- Running costs depend heavily on your electricity-to-gas price ratio and how well insulated the house is, not just which system you choose.
- A heat pump usually needs larger radiators or underfloor heating and a bigger hot water cylinder, which adds to the installed price.
- An old, poorly insulated house is the hardest and most expensive case for a heat pump, while a well-insulated newer home suits one much more easily.
What people actually paid
Real prices, in people's own words
- £2,200“Mine was £2.2k after BUS from Octopus, 8 rads.”
- £2,900“I paid £1300 (ASHP), £1000 for cylinder and another £600ish for stuff.”
- £3,000“I paid roughly £10500 for a 7kW aurotherm plus with 300l UVC, no buffer tank as one zone and full install. Minus the Home Energy Scotland Grant (£7500) I paid £3000”
- £6,500“My Octopus install cost around £11,500 and I paid £6,500 after the grant”
- £8,500“I got a full package from coolenergy, heatpump, buffer, 300l HWC, carel controller, glycol, the works. That was £6300 after vat reclaim.”
- £12,000“We where charged 12k minus the grant for an 11 KW Mitsubishi”
Genuine amounts posted publicly. We publish the price and the quote, never the person.
Why the price varies so much
The installed cost of each system depends on what your existing setup already has. Swapping a Boiler for another boiler is usually a same-day job because the pipework, radiators and flue are already sized correctly. A Heat pump asks more of the house: lower flow temperatures mean radiators often need upsizing, or the property needs Underfloor heating to work efficiently, and the hot water cylinder usually has to be replaced too. None of that is a fault of the technology, it is just what a lower-temperature heat source requires to perform well. Running costs vary just as much once the system is in. A heat pump can look expensive to run if electricity is priced much higher than gas per unit, even though it produces more heat per unit of energy used. Homes that have already had cavity wall or loft insulation done, or a wider Renovation that improved airtightness, get far more out of a heat pump than a leaky Victorian terrace with no additional work done first.
How to pay less
- Check your eligibility for the Boiler Upgrade Scheme grant before assuming a heat pump is out of reach on price.
- Get a proper heat loss survey rather than a rough estimate, since undersizing radiators or the heat pump itself causes expensive problems later.
- Improve loft or cavity wall insulation first if you can, since it lowers the running cost of either system and can reduce the size of heat pump you need.
- Compare installers on their MCS certification and after-care support, not just the headline price, since a badly commissioned heat pump runs inefficiently.
- If a heat pump is not affordable now, ask an installer whether your radiators and pipework could be sized to make a future switch cheaper.
Common questions
Is a heat pump more expensive than a boiler to install?
Usually yes, even after grant support. A heat pump often needs larger radiators, a new hot water cylinder and sometimes upgraded pipework, all of which add to the installed price compared with a like-for-like boiler swap.
Does a heat pump grant cover the whole installation?
No, the Boiler Upgrade Scheme grant reduces the cost but rarely covers it in full, and eligibility depends on your property and current heating system. Check the current scheme rules before budgeting on the assumption of full coverage.
Is a heat pump cheaper to run than a gas boiler?
It depends on your electricity and gas prices and how well insulated your home is. A well-insulated house with a correctly sized heat pump often runs cheaper than gas, while a poorly insulated older home may see smaller savings or even higher bills.
Do I need new radiators for a heat pump?
Often, yes. Heat pumps run at lower flow temperatures than boilers, so existing radiators may need to be upsized, or the house may need underfloor heating in some rooms, to keep the home properly warm.
Which is cheaper overall, a boiler or a heat pump?
There is no single answer. A boiler is usually cheaper to install and simpler for an existing gas system, while a heat pump costs more upfront but can be cheaper to run in a well-insulated home. The right choice depends on your house, not just the technology.