The Daikin Altherma 3 costs between £9,000 and £14,000 installed
The Daikin Altherma 3 is an air-source heat pump that extracts heat from outside air to warm your home and hot water. Its installed cost depends on property size, existing radiator system, and whether you choose the monobloc or split version. Daikin’s Altherma 3 monobloc typically starts at £9,000, while the split version can reach £14,000 or more (Energy Saving Trust, 2026).
These figures include the unit, hot water cylinder, installation labour, and any necessary radiator upgrades. MCS installer directory average quotes from 2026 confirm that the installed price range aligns with these figures (MCS, 2026). For a typical 3-bed semi-detached house, the installed cost sits at the lower end of this range. Larger homes or those needing significant radiator upgrades push the cost towards the upper end.
The Daikin Altherma 3 achieves a Seasonal Coefficient of Performance (SCOP) of up to 4.5, meaning it can produce 4.5 kWh of heat for every 1 kWh of electricity
The Seasonal Coefficient of Performance (SCOP) is a measure of how efficiently a heat pump turns electricity into heat over a full heating season. A higher SCOP means lower running costs. The Daikin Altherma 3 H model is rated for UK average winter conditions and achieves a SCOP of up to 4.5 (MCS product database, 2026).
A SCOP of 4.5 is higher than the typical UK air-source heat pump average of 3.2 to 3.8 (Energy Saving Trust, 2026). This means the Altherma 3 is among the most efficient models available. Higher SCOP directly lowers running costs compared to older heat pumps or gas boilers. For example, at a SCOP of 4.5, the effective cost of heat from electricity at 24p/kWh works out at roughly 5.3p per kWh of heat.
Quick numbers running costs, grant savings, and payback period for a typical 3-bed semi-detached house
The table below compares annual heating costs for a typical 3-bed semi-detached house using a gas boiler versus the Daikin Altherma 3. Figures are based on Ofgem price cap rates for January 2026 (electricity 24p/kWh, gas 10p/kWh) and a typical annual heating demand of 10,000 kWh (Ofgem, 2026).
| Metric | Gas boiler (10p/kWh) | Daikin Altherma 3 (SCOP 4.5) | Annual difference |
|---|---|---|---|
| Annual heating cost | £1,000 | £533 | £467 saving |
| Annual hot water cost (2,000 kWh) | £200 | £107 | £93 saving |
| Total annual cost | £1,200 | £640 | £560 saving |
| Upfront cost after BUS grant | N/A | £1,500 – £6,500 | N/A |
The Boiler Upgrade Scheme (BUS) grant of £7,500 reduces the upfront cost to between £1,500 and £6,500 (GOV.UK, 2026). Payback period ranges from 4 to 18 years depending on grant eligibility and existing heating system. For homes replacing electric storage heaters or oil, payback is shorter. For homes replacing a gas boiler, payback is longer.
The Daikin Altherma 3 is eligible for the Boiler Upgrade Scheme grant of £7,500, but only if installed by an MCS-certified installer
The Boiler Upgrade Scheme (BUS) provides a fixed £7,500 grant towards the cost of an air-source heat pump in England and Wales (GOV.UK, 2026). Scotland has its own Home Energy Scotland loan and grant scheme, which offers up to £7,500 for heat pumps (Energy Saving Trust Scotland, 2026).
Eligibility requires the property to have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation. If your EPC recommends loft or cavity wall insulation, you must install it before applying, or the grant will not be approved. The grant is deducted from the installer’s invoice, not paid to you directly. You must use an MCS-certified installer to qualify.
How to check your EPC for heat pump eligibility
You must use an MCS-certified and TrustMark-registered installer to qualify for the BUS grant and manufacturer warranty
Daikin requires MCS installation for the full 7-year warranty on the Altherma 3 (Daikin UK, 2026). Without MCS certification, the warranty is reduced or voided. TrustMark registration ensures the installer meets government-endorsed quality standards for workmanship and customer service (TrustMark, 2026).
To check a specific installer, use the MCS installer database or the TrustMark website. Both are free to search. Do not accept an installer who cannot provide their MCS certificate number and TrustMark registration. If you use an uncertified installer, you lose the BUS grant and risk invalidating the manufacturer warranty.
The Daikin Altherma 3 works best with large radiators or underfloor heating
The heat pump operates at lower flow temperatures (35–50°C) than a gas boiler (60–70°C). This means existing radiators may need upgrading to larger or more efficient models to deliver the same heat output. The Energy Saving Trust estimates that radiator upgrades add £500 to £2,000 to the total installation cost (Energy Saving Trust, 2026).
Properties without a hot water cylinder (e.g., combi boiler systems) will need one installed, adding £1,000 to £2,000 to the cost. Underfloor heating is ideal because it works efficiently at low flow temperatures. If your home already has underfloor heating, the Altherma 3 will work with minimal modification. If you have standard radiators, a survey will determine whether upgrades are needed.
Heat pump radiator upgrades: what to expect
Payback on a Daikin Altherma 3 typically takes 5 to 12 years after the BUS grant, depending on your current heating fuel and property insulation
For homes replacing an old gas boiler, payback is longer (8–12 years) due to lower gas prices. For homes replacing oil, LPG, or electric storage heaters, payback can be as short as 5–7 years (Energy Saving Trust payback calculator, 2026). Payback assumes current energy prices; if the electricity-to-gas price ratio narrows, payback improves.
The Department for Energy Security and Net Zero (DESNZ) heat pump cost analysis for 2026 confirms that well-insulated homes see faster payback (DESNZ, 2026). Properties with poor insulation will need higher heat output, reducing SCOP and increasing running costs. Insulation upgrades before installation improve payback significantly. If you plan to stay in your home for 10 years or more, the Daikin Altherma 3 is likely to pay back its upfront cost through lower heating bills.
Frequently Asked Questions
The Daikin Altherma 3 costs between £9,000 and £14,000 installed, according to MCS installer directory quotes from 2026. The monobloc version starts at £9,000, while the split version can reach £14,000 or more.
The Daikin Altherma 3 achieves a Seasonal Coefficient of Performance (SCOP) of up to 4.5, as certified by the MCS product database in 2026. This is higher than the UK average of 3.2 to 3.8 for air-source heat pumps.
Yes, the Daikin Altherma 3 is fully eligible for the Boiler Upgrade Scheme, which provides a £7,500 grant in 2026. This reduces the net installed cost to between £1,500 and £6,500 for most homes.
The Daikin Altherma 3 has a typical lifespan of 15-20 years with proper maintenance. Daikin offers a 2-year manufacturer warranty, extendable to 5 or 7 years through their registration programme.
For a typical 3-bed semi-detached house, an 8kW to 10kW Daikin Altherma 3 is usually sufficient. An MCS-certified installer will calculate the exact size based on your home's heat loss assessment.
