Air source heat pumps are the UK’s fastest-growing home heating technology, and for good reason – they slash carbon emissions, work in our climate, and qualify for a £7,500 government grant. But which models deliver the best performance, reliability, and value? We’ve compared the top brands on the market.
Best Air Source Heat Pumps at a Glance
| Model | Capacity | SCOP (Efficiency) | Noise Level | Est. Cost (Installed) |
|---|---|---|---|---|
| Vaillant aroTHERM plus | 3–15kW | Up to 5.08 | 54 dB | £10,000 – £14,000 |
| Daikin Altherma 3 | 4–16kW | Up to 4.64 | 55 dB | £9,000 – £12,000 |
| Samsung Gen7 EHS Mono | 5–16kW | Up to 4.65 | 47 dB | £8,500 – £11,500 |
| Mitsubishi Ecodan R290 | 5–14kW | Up to 4.30 | 58 dB | £9,500 – £13,000 |
| Nibe F2120 | 8–20kW | Up to 4.50 | 56 dB | £10,000 – £15,000 |
| Grant Aerona³ R32 | 6–17kW | Up to 4.52 | 56 dB | £8,000 – £11,000 |
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Detailed Reviews
1. Vaillant aroTHERM plus – Best Overall
Vaillant’s flagship heat pump uses R290 (propane) refrigerant, giving it one of the highest efficiency ratings on the market (SCOP up to 5.08). It achieves flow temperatures up to 75°C, meaning it can work with existing radiators in many homes without upgrading to underfloor heating.
✅ Pros
- Class-leading efficiency (SCOP 5.08)
- Works with existing radiators (75°C flow)
- Natural R290 refrigerant (low GWP)
- Extensive UK installer network
- 5-year warranty (7 with registration)
⚠️ Cons
- Higher upfront cost than competitors
- Requires 3m clearance from boundary (R290)
- Outdoor unit is slightly larger than some rivals
2. Daikin Altherma 3 – Best Value
Daikin is the world’s largest heat pump manufacturer, and the Altherma 3 is their best-selling model in the UK. It offers a great balance of performance, reliability, and price, with a proven track record across thousands of installations.
✅ Pros
- Competitively priced
- Huge installer base – easy to get serviced
- Built-in weather compensation
- Compatible with Daikin’s app for monitoring
⚠️ Cons
- Uses R32 refrigerant (higher GWP than R290)
- Max flow temp 65°C – may need radiator upgrades
- Outdoor unit can be noisy at peak load
3. Samsung Gen7 EHS Mono – Quietest
Samsung’s Gen7 heat pump is remarkably quiet at just 47dB – roughly the level of a library. It’s an excellent choice for terraced houses or properties where the outdoor unit sits near a neighbour’s window.
✅ Pros
- Ultra-quiet operation (47dB)
- Affordable compared to European brands
- Smart control via Samsung SmartThings
- R32 refrigerant with good efficiency
⚠️ Cons
- Smaller UK installer network
- Max flow temp 65°C
- Parts availability can be slower
How to Choose the Right Size Heat Pump
| Home Type | Bedrooms | Heat Loss (approx.) | Recommended Size |
|---|---|---|---|
| Well-insulated flat | 1–2 | 3–4kW | 5kW |
| Mid-terrace house | 2–3 | 5–7kW | 8kW |
| Semi-detached (average insulation) | 3 | 7–9kW | 10–12kW |
| Detached house | 4+ | 10–14kW | 12–16kW |
| Older/poorly insulated detached | 4+ | 14–20kW | 16–20kW |
Running Costs & Savings
| Heating System | Annual Fuel Cost (3-bed semi) | Annual CO₂ |
|---|---|---|
| Gas Boiler (90% efficient) | £1,050 – £1,300 | 2.7 tonnes |
| Oil Boiler (85% efficient) | £1,400 – £1,800 | 3.5 tonnes |
| Air Source Heat Pump (SCOP 3.5) | £850 – £1,100 | 0.9 tonnes |
| Direct Electric Heating | £2,200 – £2,800 | 1.6 tonnes |
The Boiler Upgrade Scheme (£7,500 Grant)
The UK government’s Boiler Upgrade Scheme (BUS) offers a £7,500 grant towards the cost of an air source heat pump. After the grant, a typical installation costs £3,000–£7,000 out of pocket. The scheme is available in England and Wales through to 2028.
- Property must have an EPC (any rating)
- Must replace an existing fossil fuel heating system
- Installer must be MCS-certified
- The installer applies for the voucher on your behalf
Frequently Asked Questions
Do heat pumps work in cold UK winters?
Yes. Modern air source heat pumps work efficiently down to -20°C. Even at 0°C outside, a good heat pump achieves a COP of 2.5–3.0, meaning it produces 2.5–3x more heat energy than the electrical energy it consumes. The UK rarely drops below -5°C for extended periods.
How noisy are heat pumps?
Modern models produce 42–58dB, similar to a fridge or quiet conversation. Planning regulations require the unit to be at least 1 metre from a property boundary and not exceed 42dB at the nearest neighbour’s window. Most quality installations meet this easily.
Do I need underfloor heating?
Not necessarily. Heat pumps work most efficiently at lower flow temperatures (35–45°C), which suits underfloor heating perfectly. However, many modern heat pumps (like the Vaillant aroTHERM plus) can reach 75°C, allowing them to work with standard radiators. You may need slightly larger radiators in some rooms.
How long do heat pumps last?
A well-maintained air source heat pump typically lasts 20–25 years – significantly longer than a gas boiler (12–15 years). Annual servicing costs around £100–£200.
Learn More About Heat Pumps
Our complete heat pump guide covers installation, costs, and everything else you need to know.