How a heat pump actually works
An air source heat pump doesn't burn anything. It extracts heat from outside air — even in freezing weather — and moves it into your home. For every 1 kWh of electricity it uses, it delivers 2.5–5 kWh of heat. A gas boiler tops out at around 90% efficiency; a heat pump runs at a SCOP of 250–500%, averaged over the year. That efficiency gap is where the savings come from, especially for homes currently on oil, LPG or electric heating.
The grant does the heavy lifting
The UK Government's Boiler Upgrade Scheme knocks £7,500 off an air source heat pump installation — and £9,000 if your home is currently heated by oil or LPG. The grant doesn't need repaying, and as your MCS certified installer we apply for it on your behalf: you only ever see the after-grant price. Combined with a solar and battery system powering it with your own generation, running costs fall further still.
Sized from a real heat loss survey
The single biggest factor in whether a heat pump delights or disappoints is sizing. We carry out a full room-by-room heat loss calculation before quoting — insulation, glazing, radiator sizes, hot water demand — and design the system around the results. No guesswork, no "one size fits all", and honest advice if your home needs insulation work first.
Hardware we install
We fit heat pumps from Vaillant, Worcester Bosch and Ideal Heating — quiet, proven units with strong UK support networks and long warranties. Installation typically takes 2–3 days including the hot water cylinder, and every system is commissioned and MCS certified for the grant.
| Range | Typical output | SCOP (35°C flow) | Sound (max) | Warranty | Best for |
|---|---|---|---|---|---|
| Vaillant aroTHERM plus | 3.5, 5, 7, 10, 12 kW | ~4.7 | 44 dB(A) @ 3m | 7 years | Quiet operation, tight garden clearances |
| Worcester Bosch CS7000iAW | 5, 7, 9, 12 kW | ~4.6 | 46 dB(A) @ 1m | 7 years (extendable) | Homeowners who want a household boiler brand |
| Ideal Logic Air | 4, 6, 8, 10, 12, 16 kW | ~4.6 | 52 dB(A) @ 1m | 7 years | Best £/kW when combined with an Ideal cylinder |
All three run on R290 (propane) refrigerant — high efficiency and low global-warming potential. The best choice depends on your heat loss result (which determines the required output), your outdoor space, and whether you already have a preferred cylinder brand.
What does a heat pump actually cost?
Real-world pricing after the £7,500 Boiler Upgrade Scheme grant, for the type of homes we typically install for across the North West in 2026:
| Property | Typical heat loss | System size | Indicative price after grant |
|---|---|---|---|
| 2-bed terrace, decent insulation | ~4 kW | 5 kW ASHP + 180 L cylinder | £3,500 – £5,500 |
| 3-bed semi, cavity walls insulated | ~6 kW | 7 kW ASHP + 210 L cylinder | £4,500 – £7,000 |
| 4-bed detached, mixed insulation | ~9 kW | 10 kW ASHP + 250 L cylinder | £6,000 – £9,500 |
| Larger period property, some radiator upgrades | ~12 kW | 12 kW ASHP + 300 L cylinder + rads | £8,000 – £12,500 |
For oil and LPG homes the grant is £9,000 — knock a further £1,500 off each of the ranges above. All prices include commissioning, MCS certification and the grant application.
Running costs vs your current fuel
Because a heat pump delivers 3+ units of heat per unit of electricity, the comparison isn't fuel-price-per-kWh — it's fuel-price divided by boiler efficiency vs electricity-price divided by SCOP. Worked out for a typical home needing 12,000 kWh of heat per year:
| Current fuel | Effective p/kWh of heat | Annual heating cost | Heat pump on heat-pump tariff | Annual saving |
|---|---|---|---|---|
| Mains gas (90% boiler) | ~7.0p | £840 | £680 (SCOP 3.5, 17p/kWh) | ~£160/yr + gas standing charge |
| Oil (85% boiler) | ~8.5p | £1,020 | £680 | ~£340/yr |
| LPG (85% boiler) | ~12.4p | £1,490 | £680 | ~£810/yr |
| Electric storage/panel | ~24p | £2,880 | £680 | ~£2,200/yr |
The gas comparison is close on standard tariffs — the saving grows if you disconnect gas entirely (~£110/yr standing charge back), pair the heat pump with solar, or use a dedicated heat-pump tariff. Oil, LPG and electric homes see the biggest immediate saving.
Will my radiators need upgrading?
A heat pump runs happiest at a flow temperature of around 45°C — cooler than a boiler (typically 65–75°C). To move the same heat into a room at a lower temperature, some radiators need to be larger. In our surveys across the North West we find about 60% of homes can keep every radiator, 30% need one to three radiators swapped (usually the smallest, in the coldest rooms), and around 10% benefit from a broader upgrade. Underfloor heating and modern K3 panel radiators work particularly well.
We include the radiator plan in your written proposal — no surprises after installation, no "surveys we didn't quote for". If your fabric needs work first (loft top-up, cavity fill, draught proofing) we'll tell you honestly rather than sell you a bigger heat pump to compensate.
Solar + battery + heat pump — how it stacks
A heat pump uses roughly 3,000–4,000 kWh of electricity a year for an average home. Adding solar covers a decent chunk of the shoulder-season load; adding a battery lets you run the heat pump on cheap overnight electricity even when the panels aren't producing. Homes that combine all three routinely see winter electricity bills that are lower than their old gas-only bills, and near-zero bills for six months of the year.
You don't have to do it all at once — see our solar and battery storage pages for phased approaches — but the maths only ever get better as you add each layer.
See what your home qualifies for
Free heat loss survey and a fixed after-grant price. No pushy salespeople — just engineers.
Get a free quote todayHeat pump FAQs
How much is the heat pump grant worth?
The Boiler Upgrade Scheme (BUS) gives £7,500 towards an air source heat pump — rising to £9,000 for homes currently heated by oil or LPG. It doesn't need repaying, and we apply on your behalf.
Do heat pumps work in cold weather?
Yes — modern units extract heat from outside air at temperatures as low as -20°C, and heat pumps are standard in Norway and Sweden. Efficiency drops as it gets colder, which is why correct sizing from a heat loss survey matters.
Will a heat pump work with my radiators?
Often, yes. Around 60% of the homes we survey in the North West can keep every radiator; another 30% need 1–3 upsized; and about 10% benefit from a broader upgrade. Heat pumps run at lower flow temperatures than boilers, so some homes need a few radiators upsized. Our heat loss survey identifies exactly which, before you commit to anything.
How much does a heat pump cost to run?
A heat pump delivers 2.5–5 units of heat per unit of electricity — a SCOP of 250–500%, averaged over the whole year, versus ~90% for a gas boiler. On a heat-pump tariff (around 17p/kWh) most well-installed systems match or beat mains gas running costs, and beat oil, LPG and electric heating by a wide margin.
How long does installation take?
A typical air source heat pump installation takes 2–3 days, including the hot water cylinder and any radiator changes identified in the survey.
How noisy is a heat pump?
Modern units run at around 40–48 dB(A) at 1 metre when working — quieter than a normal conversation. MCS installation standards require the sound pressure at your neighbour's nearest window to be below 42 dB(A), which we calculate as part of the design. In practice a heat pump is quieter than a fridge from a metre away.
Do I need planning permission for a heat pump?
Most air source heat pumps fall under permitted development in England, provided the unit is at least 1 metre from the boundary, the total volume is under 1.5 m³, and it's not sited on the front elevation of a listed building or conservation area property. We check planning as part of the survey and handle any application if needed.
Can I use my existing hot water cylinder?
Usually not. Heat pumps need a cylinder with a larger coil surface area than a standard boiler cylinder, so a new cylinder is included in almost every install. We size it to your household (typically 180–300 L) and factor it into the price you see.
Related guides: The complete ASHP guide for UK homeowners