In 2026, over 60,000 heat pumps were installed under the Boiler Upgrade Scheme, with Daikin, Mitsubishi Electric, and Vaillant accounting for the majority of the market share (DESNZ, 2026).
More than 60,000 heat pumps were installed through the Boiler Upgrade Scheme (BUS) in 2026. Three brands dominated that market: Daikin, Mitsubishi Electric, and Vaillant. Each brand takes a different engineering approach, which affects how well a heat pump will perform in your home. Your choice should depend on four factors: efficiency at low temperatures, noise output, upfront cost, warranty length, and how easy it is to find a local installer.
Daikin typically costs £500–£800 more than Mitsubishi but maintains a COP above 3.0 down to -15°C. Mitsubishi is the quietest at 55 dB(A). Your choice depends on cold-weather performance, noise tolerance, and budget.
- Daikin maintains COP above 3.0 down to -15°C for cold climates.
- Mitsubishi Electric offers the quietest operation at 55 dB(A).
- Vaillant heat pumps are typically £500–£800 cheaper than Daikin.
- Choose Mitsubishi for outdoor units near bedroom windows.
- Check MCS database for real performance data before buying.
- In 2026, over 60,000 heat pumps were installed under the Boiler Upgrade Scheme, with Daikin, Mitsubishi Electric, and Vaillant accounting for the majority of the market share (DESNZ, 2026).
- Daikin leads in cold-climate performance and inverter technology
- Mitsubishi Electric offers the quietest operation and longest warranty
- Vaillant provides the best integration with existing gas heating systems
- Quick numbers key specs for a typical 8 kW system
- How to choose match the brand to your home’s heat loss and outdoor space
- Eligibility and installer verification MCS certification is mandatory for the £7,500 grant
Daikin leads in cold-climate performance and inverter technology
Daikin’s Altherma 3 range uses a high-temperature inverter compressor. This maintains a coefficient of performance (COP) above 3.0 down to -15°C, according to Daikin’s published MCS performance data (MCS Database, 2026). COP measures how many units of heat a heat pump produces for each unit of electricity it uses. A COP of 3.0 means three units of heat for one unit of electricity.
This cold-weather performance makes Daikin a strong choice for homes with existing radiator systems that need flow temperatures above 55°C. Many older radiators were designed for gas boilers running at 70–80°C, so a heat pump that can deliver higher flow temperatures avoids the cost of replacing all radiators.
The trade-off is cost. For an equivalent 8 kW capacity, Daikin typically costs £500–£800 more than a Mitsubishi unit before the BUS grant (Energy Saving Trust, 2026).
Mitsubishi Electric offers the quietest operation and longest warranty
Mitsubishi’s Ecodan SUZ-SWM range has a sound power level as low as 55 dB(A) at 1 metre (MCS Database, 2026). Sound power level is the total noise emitted by the unit, measured in decibels. For context, 55 dB(A) is quieter than a typical conversation. This makes Mitsubishi the best option if your outdoor unit must be placed near a bedroom window or a neighbour’s boundary.
The standard warranty is 5 years. This can be extended to 10 years if the unit is installed by an MCS-registered installer and registered within 30 days (Mitsubishi Electric UK warranty terms, 2026). The trade-off is slightly lower COP at -10°C compared to Daikin’s equivalent model, typically about 2.8 versus 3.1 (MCS Database, 2026).
Vaillant provides the best integration with existing gas heating systems
Vaillant’s aroTHERM plus is designed to work as a hybrid system with Vaillant gas boilers. The sensoCOMFORT control automatically switches between the heat pump and gas boiler depending on which is more efficient at that moment (Vaillant UK technical guide, 2026). This is useful for homes not yet ready for full electrification, or where outdoor space is limited and a larger heat pump cannot be installed.
The trade-off is that the aroTHERM plus has a lower standalone COP than Daikin or Mitsubishi at full load, typically around 2.9 at 35°C flow temperature (Energy Saving Trust, 2026). If you already have a Vaillant boiler and want to keep it as backup, this brand offers seamless integration. If you are removing gas entirely, Daikin or Mitsubishi may give better efficiency.
Quick numbers key specs for a typical 8 kW system
| Metric | Daikin Altherma 3 | Mitsubishi Ecodan SUZ-SWM | Vaillant aroTHERM plus |
|---|---|---|---|
| COP at 35°C flow | 3.35 | 3.20 | 2.90 |
| Sound power level (dB(A)) | 62 | 55 | 60 |
| Maximum flow temperature | 65°C | 60°C | 65°C |
| Warranty (years) | 5 | 5 (extendable to 10) | 5 |
| Approximate installed cost (BUS deducted) | £6,500–£8,000 | £5,800–£7,200 | £6,000–£7,500 |
Costs assume a standard 8 kW air-source heat pump installed in a typical 3-bed semi-detached home, with the £7,500 BUS grant deducted. COP figures are from the MCS Heat Pump Database (MCS Database, 2026). Sound levels are from manufacturer datasheets. Installed cost ranges are based on Energy Saving Trust typical installation cost tables (Energy Saving Trust, 2026).
How to choose match the brand to your home’s heat loss and outdoor space
Choose Daikin if your home has existing radiators that need flow temperatures above 55°C, or if you live in a colder region where winter temperatures regularly drop below -10°C. Choose Mitsubishi if noise is a concern because the outdoor unit is near a bedroom, or if you want the longest possible warranty. Choose Vaillant if you already have a Vaillant gas boiler and want a hybrid system, or if outdoor space is too small for a standalone heat pump.
No single brand is universally best. The decision depends on the heat loss calculation done under MCS standard (MCS, 2026) and where the outdoor unit can be placed. A heat loss calculation measures how much heat your home loses on the coldest day of the year. This tells you what size heat pump you need. If the calculation shows low heat loss (below 6 kW), any of the three brands will work well. If heat loss is higher, Daikin’s cold-climate performance becomes more important.
How to read a heat loss calculation report
Eligibility and installer verification MCS certification is mandatory for the £7,500 grant
The Boiler Upgrade Scheme gives you a £7,500 grant towards an air-source heat pump. To claim it, you must use an MCS-certified installer and an MCS-certified product (GOV.UK, 2026). All three brands are MCS-registered, but not every installer carries all brands. Check the MCS installer register at mcscertified.com to find local installers who carry your chosen brand.
You should also check that the installer holds TrustMark registration for consumer protection (TrustMark, 2026). The grant is deducted from the invoice by the installer, not paid to you. You do not need to repay it. The grant amount is fixed at £7,500 for air-source heat pumps in 2026 (GOV.UK, 2026).
Boiler Upgrade Scheme eligibility checklist
Frequently Asked Questions
Daikin's Altherma 3 range leads in cold-climate performance, maintaining a COP above 3.0 down to -15°C according to MCS Database data (2026).
Mitsubishi Electric's Ecodan SUZ-SWM range has a sound power level as low as 55 dB(A) at 1 metre, quieter than a typical conversation, per MCS Database (2026).
Yes, for an equivalent 8 kW capacity, Daikin typically costs £500–£800 more than a Mitsubishi unit before the BUS grant, according to Energy Saving Trust (2026).
Mitsubishi Electric offers a longer standard warranty than Daikin or Vaillant, but exact terms depend on the installer and registration. Check with your local MCS-certified installer.
Yes, Vaillant heat pumps work well in older homes with existing radiator systems, but you may need to replace some radiators for best efficiency. Compare flow temperature requirements with your installer.
