Air Source Heat Pump Installation Costs & Prices 2021

Air source heat pumps are a highly efficient heating technology that generate heat from air compression. 

Effective all year round even at temperatures below -15°C, heat pumps are well-suited to the UK climate and are currently heavily incentivised by the UK government under the Renewable Heat Incentive (RHI)

As a result, UK installations skyrocketed to 250,000 in 2019, according to Statista

Air source heat pumps combine perfectly with underfloor heating systems to offer one of the most efficient and greenest home heating systems possible. 

This article will cover what you can expect to pay for an air source heat pump, factors that can affect the cost and other common questions around air source heat pumps.

Average Heat Pump Installation Cost

By collecting quotes from 5 MCS-certified air source heat pump installers, 8 secondary sources and a government source, we compiled this table of average air heat pump installation costs. 

These costs are for retrospective fitting to existing heating systems and do not include underfloor heating costs. 

Installation in new builds may be cheaper, especially when installed at the same time as an underfloor heating system. 

SizeDurationCost
2-bed terraced/semi-detached (5kW)1 - 2 days£6,000 to £8,000 
3-bed semi-detached (9kW to 12kW)1 - 2 days£8,000 to £10,000
4-bed semi-detached (16kW)1 - 3 days£10,000 to £14,000
4-bed detached or larger (16kW)2 - 4 days£15,000 to £20,000

All costs include the following equipment and parts as well as labour:

  1. The heat pump unit itself
  2. Water tank 
  3. Circulation pumps
  4. Buffer tank 
  5. Heat exchanger 
  6. All connective components 
  7. Heat distribution systems may be necessary for bigger homes

Heat Pump Power Rating

Measured in kW, heat pumps have varying power ratings. Smaller heat pumps are rated around 4kW to 5kW, suitable for flats or smaller houses.

8 to 12kW heat pumps are the most common option for 3-bed semi-detached houses, 16kW heat pumps are usually only necessary for larger detached homes. 

The installation engineer will survey your house size as well as its energy credentials and usage prior to recommending a heat pump model.

What Are Air Source Heat Pumps?

Air source heat pumps are a type of low carbon heating technology with high efficiency and lower running costs than most other heating systems. 

Air source heat pumps pump the air from outside to a compressor which compresses and heats the air. The heat is then pumped to radiators, underfloor heating and hot water plumbing. 

This is why heat pumps are so efficient – they don’t really create heat energy, but simply move it from one place to another. 

Air to Water Heat Pumps

There are two types of air-source heat pumps: air-to-air heat pumps and air-to-water heat pumps

Air-to-air heat pumps are best thought of as reverse air conditioning with additional heating via air compression. 

They do not directly connect to a home’s wet heating system, so you can’t so easily use them to heat water like you can with an air-to-water heat pump. 

Air-to-water heat pumps, however, are linked to a house’s wet central heating system. This means that both space and water heating are provided for by the heat pump – much more efficient than air to air heating in domestic properties. 

It’s worth noting that you’ll need an air-to-water air source heat pump to claim RHI in the UK – these are the favoured heat pumps for all domestic heating purposes.

How Much Can You Save With an Air Source Heat Pump?

Air source heat pumps can be 4 or more times more efficient than either gas or electric heating. 

Their efficiency is actually around 350% – they use such a small amount of electricity to create heat that their efficiency sits well into the positive range. 

In terms of cost per kWh, air source heat pumps costs are very similar to highly efficient modern gas boilers at just under 5p/kWh, but it depends on the tariff. 

Average Air Source Heat Pump Heating Cost

According to IMS Heatpumps, a very raw average annual heating cost average when using an air source heat pump is £520. 

Viessman similarly states that the average cost of heating an average UK home using an air source heat pump would cost £560 (based on 12,000kWh yearly usage).  

Heat pumps are reliable with low maintenance costs and require servicing just once around every 20 years vs 8 to 12 years for gas boilers, which also lowers long-term costs. 

Whilst air source heat pumps are very efficient – and therefore eco-friendly – they still run on electricity which is around 4 times more expensive than gas. This explains why costs are comparable to gas heating, but still lower on some tariffs. 

In short, air-source heat pumps do not generally yield tremendous energy savings in their own right, but that doesn’t paint the whole picture. You also have to take RHI payments into account.

RHI Payments

The RHI scheme pays a quarterly tariff based on how much energy you ‘generate’ with your heat pump. The current tariff as of 2021 is 10.85p/kWh. These payments last for 7 years. 

The RHI in its current form will close on 31 March 2022 and will be replaced by the Clean Heat Grant, which will be a more traditional-style grant design to cover installation costs. 

Whilst there are little details of the Clean Heat Grant, the RHI is currently generous enough to recover the majority of your heat pump’s upfront cost over the 7 years (or even leave you in profit), providing your house is very well-insulated.

For your system to qualify, the equipment and installer must be registered by the Microgeneration Certification Scheme (MCS).

Property SizeRHI Payments (over 7 years)
1-Bed Semi£6,076
2-Bed Semi£9,114
3-Bed Detached£12,912

Source: Ofgem

Green Homes Grant 

You can also account for some of the initial costs of an air source heat pump using the government’s Green Homes Grant. 

As of 2021, the Green Homes Grant can provide a voucher of up to £5,000 (or £10,000 for some low-income households), designed to cover a multitude of home improvements that yield green or low-carbon outcomes. 

The eligibility criteria specify that your home must already have high-grade wall, loft or cavity insulation suitable for low-carbon heating. You can pay for either the pump or the insulation using the Green Homes Grant. 

Air Source Heat Pump Installation Process 

Air source heat pumps are generally fairly small, resembling that of an air-conditioning unit. 

They usually ‘plug in’ to a home’s existing hot water heating – installation can take as little as a few hours. There must be space for the water tank – this will influence the position of the pump unit. 

A large portion of the cost is accounted for by the price of the pumping unit itself, generally costing £3,000 at a minimum. 

Whilst the standards of heat pumps are generally high, pricier Samsung or Mitsubishi pumps can cost £1,000 to £2,000 more than cheaper models. 

Do Air Source Heat Pumps Require Planning Permission?

As of 2011, heat pumps are considered Permitted Development, and therefore do not require planning permission subject to the following terms:

  • Must comply with MCS
  • The outdoor unit itself does not exceed 0.6 cubic metres. This means larger dual-impeller units may require planning permission. 
  • Must not be positioned closer than 1 metre from the boundary. 
  • Must cause minimal impact to the appearance of the property (pump noise is also worth taking into account)
  • Can only be used for heating purposes
  • Buildings exempt from Permitted Development (e.g. Listed Buildings) do not apply 

You can find full details on the Government’s Planning Portal.

Do You Need Underfloor Heating To Install a Heat Pump?

Strictly speaking, you can run an air-to-water air source heat pump with radiators. 

However, since air source heat pumps are most efficient at a lower heat, they’re ideally partnered with underfloor systems. 

Common house radiators are quite small, and thus, they have to generate much higher temperatures to radiate their heat through an interior space. 

Contrastingly, heat pumps work best when their heat is dispersed over a larger area – ideal for underfloor heating. 

It may be necessary to fit oversized radiators with a heat pump if your current radiators are too small and you don’t want underfloor heating. 

It’s safe to assume that heat pumps will rarely work with standard gas heating radiators.

Insulation

Insulation is a very important prerequisite for the installation of any air source heat pump and will vastly improve heat retention and efficiency. 

You can consider applying for a Green Homes Grant to assist in the cost of insulation. Insulation can cost north of £10,000 depending on the size of the property and its age. 

Newer homes are less likely to require insulation upgrades. You can ask most heat pump installers to advise on your insulation when they conduct a survey of your home prior to installation. 

Get Prices on Air Source Heat Pumps Near You

We’ve done our best to give you a good idea of what you can expect to pay for an air source heat pump.

However, our guides are not a substitute for a fixed quote specifically for you.

We work with all the best air source heat pumps experts ready to price your job. Get free, no-obligation quotes in your local area and compare prices using the form below.

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