Glossary · Heat pumps, grants and regulations
Are heat pumps worth it?
A heat pump is worth it when the home holds heat well, the heating system can run at lower temperatures and the grant and running costs add up. It is a poor fit for a draughty, poorly insulated house with small radiators. Modern units keep working below freezing, though efficiency falls as it gets colder.
Key points
- Worth depends on the house. Daikin says a poorly insulated home forces the heat pump to work harder, which cuts efficiency and raises running costs.
- Manufacturers say modern air source units keep producing heat in cold weather: Worcester Bosch quotes -15°C and Daikin quotes down to -25°C or -28°C, depending on the model.
- Efficiency still falls in cold weather. Daikin says electricity use rises and SCOP drops when it is colder.
- The Boiler Upgrade Scheme takes £7,500 off an air source heat pump installed by an MCS certified installer, if it replaces a fossil fuel system.
- Daikin puts air source heat pump running costs as broadly comparable with a modern gas boiler at current prices, so the case rests on the grant, insulation and your tariff.
What decides whether a heat pump is worth it
There is no single answer. Three things decide it: how well the house keeps its heat, whether the heating system can run at a lower temperature, and what you pay once the grant is taken off.
Start with the house. Daikin says a poorly insulated home forces the heat pump to work harder, which reduces efficiency and raises running costs. It says properties with solid walls, single glazing and no loft insulation may need significant upgrades before a heat pump performs well, and that a heat loss calculation by a qualified professional is the foundation of a good design.[3]Daikin UK, Types of Heat Pumps: Which One Is Right for Your Home? See loft insulation and cavity wall insulation.
Then the emitters. Daikin says traditional radiators are typically smaller and designed for higher flow temperatures, so radiator upgrades may be recommended in some properties.[2]Daikin UK, Air source heating explained Underfloor heating suits a heat pump because it runs at low temperatures.[3]Daikin UK, Types of Heat Pumps: Which One Is Right for Your Home?
Do heat pumps work in cold weather?
Yes, within limits. Worcester Bosch says modern air source heat pumps can still produce heat from outdoor temperatures as low as -15°C.[1]Worcester Bosch, Hybrid Heating Systems Daikin says modern air source units extract heat even at -25°C, and quotes -28°C as the operating limit for one of its models.[2]Daikin UK, Air source heating explained The limit varies by product, so check the data sheet.
A heat pump still works harder when it is cold. Daikin says electricity use and running costs rise in colder months, and that SCOP drops in colder weather.[7]Daikin UK, Heat pump power consumption guide This is why sizing matters, and why some people choose a hybrid heat pump that hands over to a boiler at the coldest times. For the efficiency numbers, see COP and SCOP.
Grant and running costs
The Boiler Upgrade Scheme covers England and Wales. It pays £7,500 towards an air source heat pump and £7,500 towards a ground source one, and until March 2027 an extra £1,500 if the home is heated by oil or LPG and has no mains gas.[4]GOV.UK, Apply for the Boiler Upgrade Scheme You must own the property and be replacing a fossil fuel system, and the installer applies for you.[4]GOV.UK, Apply for the Boiler Upgrade Scheme BASI says it is MCS certified and deducts the grant from the invoice, so you pay the net figure.[6]BASI Heating, Air source heat pumps, grant applied for you
On running costs, Daikin says an air source heat pump costs approximately £800 to £1,000 a year for heating, broadly comparable with a modern gas boiler at current energy prices.[3]Daikin UK, Types of Heat Pumps: Which One Is Right for Your Home? That is a manufacturer estimate and your own figure will depend on the house and your tariff.
Example
Mohammed and Farah live in a 1930s semi in Bradford with a loft that is already insulated and cavity walls that are filled. Their radiators are original. They use the GOV.UK checker, which asks for the nation, the heating type and the number of bedrooms and then compares cost and carbon savings.[5]GOV.UK, Check if a heat pump could be suitable for you They book a survey. The engineer checks the radiator sizes against the heat loss. The £7,500 grant comes off the quote.[4]GOV.UK, Apply for the Boiler Upgrade Scheme
What people get wrong
The usual mistake is to ask whether a heat pump is worth it in general. The useful question is whether this house is ready, because a poorly insulated home with small radiators will cost more to heat.
BASI says it will tell you at the survey if a boiler is the better fit and will quote that beside the heat pump.[6]BASI Heating, Air source heat pumps, grant applied for you
The other mistake is to assume cold weather rules heat pumps out. A quoted operating limit is the lowest temperature at which a unit still runs. It does not mean the unit is as efficient there as it is on a mild day.
The bottom line
A heat pump is worth it when the house keeps its heat, the radiators or underfloor heating can work at a lower temperature, and the grant cuts the upfront cost. Cold weather does not stop modern units, although it reduces their efficiency. A survey that checks heat loss and radiator sizes is the proper way to decide, and a quote for a new boiler beside it shows the difference. See heat pump vs gas boiler.
Common questions
Do heat pumps work in cold weather?
Yes, within limits. Worcester Bosch says modern air source units can produce heat from outdoor temperatures as low as -15°C, and Daikin quotes -25°C to -28°C for its units. Output and efficiency fall as it gets colder, so sizing matters.
Will a heat pump work in an old, poorly insulated house?
Possibly, but it may need work first. Daikin says homes with solid walls, single glazing and no loft insulation may need significant upgrades before a heat pump performs efficiently. A professional heat loss calculation shows what is needed.
How much is the heat pump grant?
The Boiler Upgrade Scheme gives £7,500 towards an air source heat pump and £7,500 towards a ground source one, in England and Wales. Until March 2027, off-gas homes heated by oil or LPG can get an extra £1,500.
Is there an official way to check if my home suits a heat pump?
Yes. GOV.UK has a Check if a heat pump could be suitable for you service. It asks which nation you live in, your heating type and the number of bedrooms, then compares cost and carbon savings.
Sources
We cite the original source for every figure: government, regulators, standards bodies and manufacturers' own documents. Each one shows the date we last checked it.
- Worcester Bosch. Hybrid Heating Systems. Checked 11 November 2026. ↩
- Daikin UK. Air source heating explained. Checked 11 November 2026. ↩
- Daikin UK. Types of Heat Pumps: Which One Is Right for Your Home?. Checked 11 November 2026. ↩
- GOV.UK. Apply for the Boiler Upgrade Scheme. Checked 11 November 2026. ↩
- GOV.UK. Check if a heat pump could be suitable for you. Checked 11 November 2026. ↩
- BASI Heating. Air source heat pumps, grant applied for you. Checked 11 November 2026. ↩
- Daikin UK. Heat pump power consumption guide. Checked 11 November 2026. ↩