Air-to-Water Heat Pumps

Air-to-water heat pumps cut energy bills and reduce carbon footprint substantially. Heat Pumps UK provides a one-stop resource for homeowners and businesses looking to modernise their heating system. We can even help you find a grant towards the cost of heat pump installation.
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What Is an Air-to-Water Heat Pump?

Air-to-water heat pumps are a type of air source heat pump and are the most commonly adopted option in the UK. They are becoming increasingly popular as a cost-effective, low-carbon heating solution and alternative to a new gas boiler or other fossil fuel powered heating system.

An air to water heat pump system harnesses heat from the outside air to run water-based central heating such as radiators or an underfloor heating system. This can also be used to provide domestic hot water to kitchen and bathroom sinks, showers, and baths, though a water storage tank would usually be required.

Why Choose an Air-to-Water Heat Pump?

More than 200,000 heat pumps have so far been installed across the UK — the majority of these being air source heat pumps of the air to water type — with numbers of heat pump installations hitting record levels in 2023. 

The rise of heat pumps is being driven by demand for low-carbon heating technologies to replace fossil fuel heating such as a gas or oil boiler. This type of energy efficient heating is being promoted by government-supported grants. The government has set a target of 600,000 heat pump installations a year by 2028. 

Air-to-water heat pumps cut fuel bills, reduce carbon emissions, and attract a wide range of free funding towards installation costs. In most cases, they’re likely to be several times more energy efficient than existing boilers – one unit of electricity would generate three to five units of energy.

Heating Plus Cooling

Besides keeping you warm in colder months, air-to-water heat pumps also maintain homes and business premises at a cooler, comfortable temperature during hot summer weather. They can do this because they use the same refrigeration technology as an air conditioner.


Are Solar Assisted Heat Pumps Right For Me? 

It’s a valid question. If you’re going to spend money installing solar assisted heat pumps for your home, then making sure it works for you and your home is vital. So, what are the things you need to think about to ensure you’re making the right decision?

Things To ConsiderAdditional Thoughts
Do you need heat for your home as well as your water?Solar assisted heat pumps are only suitable for heating your water in a home, so if you don’t have a system in place to heat your home, you’ll need to consider that. If you need a heat pump to do both, then it’s a good idea to choose air source heat pumps instead.
Do you currently have hot water cylinders?You’ll need a hot water cylinder to store the water with a solar assisted heat pump because it produces a constant, steady stream of hot water, but can’t produce hot water on demand like a boiler can. Some solar assisted heat pumps have a hot water cylinder built-in, but if yours doesn’t then you’ll need to find a cupboard indoors to store it in – preferably one that’s well insulated to keep the heat in when storing. 
Is your home suitable for the installation?Making room for the heat pump will mean finding the right roof or wall space outside for it. And, since it’s solar assisted, it’ll need to be in a spot with plenty of sun for it to work as efficiently as possible. Whilst it still works in the shade, the more sun a solar assisted heat pump gets the better it will perform – so you’ll need to consider if you have a spot that would work at your property.
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Find the best heat pump for your home.

You can start bringing your energy costs under control and reducing your carbon footprint right now.

We’ll put you in touch with our expert, accredited partner heat pump installers. They’ll help you make an informed decision on the best air-to-water heat pump for your home or business.

Plus, we’ll source the best free heat pump funding and discounts you can get.

How Do Air-to-Water Heat Pumps Work?

Air-to-water heat pumps heat a property in cold weather and keep it cool when temperatures rise.

The Heating Process

  • An outdoor unit with a fan draws in heat from ambient air.
  • The heat evaporates a liquid coolant, turning it into gas.
  • A compressor increases the temperature of the gas.
  • A heat exchanger releases the heat to a hot water reserve tank.
  • Hot water from the tank is circulated to the heating system and hot water supply.
  • Cold water circulates back into the heat pump.
  • The heating process is then repeated.

The Cooling Process

  • In cooling mode, the air-to-water heating process is reversed.
  • The heat pumps cool water by switching the role of evaporator coils and condenser coils. This reverses the flow of refrigerant.
  • Warm air from the building is passed through the heat exchanger and cooled by chilled water pumped through a convector.  The cool air is then directed back into rooms.
  • You still get a hot water supply because the cooling process is separate from the heating and hot water circuit.

Air-to-Water Heat Pumps Vs Boilers

Boilers generate heat by burning fuel. Air-to-water heat pumps harness thermal energy from a natural, external source that’s renewable.

This greener technology makes heat pumps far more energy efficient and cost effective than gas boilers. Seventy-five percent of the energy heat pumps use is produced by the surrounding environment.


Air-to-Water Heat Pumps

Gas boilers are 65 to 90% energy efficient, depending on age.Efficiency of 300 to 500%.
Gas is an expensive fuel.Cost effective, running on a small amount of electricity.
Boilers contribute to climate change by releasing carbon emissions.Heating bills are reduced by up to 40%.
They require regular maintenance.Low carbon output.
Boiler repairs can be costly.Minimal maintenance needed.
The government is phasing out installation of new gas boilers.Heat pumps last longer than gas boilers – 20 to 25 years.


Air-to-Water Heat Pumps Vs Air-to-Air Heat Pumps

There are two main types of air source heat pumps: air-to-water and the less common air-to-air system. 

Air-to-Air Heat Pump

Air-to-Water Heat Pump

Extracts heat from air outside a property and circulates it through the building with fans. Has additional components including a hot water tank.
Simpler installation but needs air ducts running throughout the property.Can supply a hot water system as well as heating rooms. 
Provides heating but can’t feed a hot water supply. Typically costs more.
Can’t be connected to a central heating system.May need to install a hot water cylinder.


Ground Source Heat Pumps Vs Air-to-Water Heat Pumps 

Instead of extracting heat from the air in an outdoor space, a ground source heat pump harnesses underground heat from around a building and transfers it into the property. These heat pumps have a similar efficiency level as air-to-water heat pumps but cost at least twice as much, depending on the groundwork involved.

Ground Source Heat Pump

Air-to-Water Heat Pump

Expensive, complex installation.Simpler, less costly installation.
Large area of land may be required.Flexible external location options.
More suitable for new-builds.Suitable for all types of homes.
300 to 400% energy efficiency.Up to 500% efficiency.
Efficiency depends on the type of soil or bedrock.No groundworks or underground pipe loops necessary.


Water Source Heat Pumps Vs Air-to-Water Heat Pumps

Water source heat pumps extract heat from a body of water near a property – a lake, river, the sea, or under the ground.

Water Source Heat Pump

Air-to-Water Heat Pump

Most efficient type of heat pump – heat flows more effectively through water.Slightly lower efficiency potential.
Property needs to be near a sustainable source of water.Draws heat from a readily available source – the air.
Installation can be difficult.May cost slightly more, depending on property size.
Environmental regulations apply and a licence may be required.Easier installation, with no need for submerged pipework, and typically no need for planning permission.


How Do Air-to-Water Heat Pumps Work?

For many properties, the advantages of air-to-water heat pumps outweigh the drawbacks, especially in the long term. But it’s important to understand the pros and cons before committing to heat pump installation.



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Find the best heat pump for your home.

Making Your Decision

Heat Pumps UK makes it easier to decide whether installing an air-to-water heat pump is worth the investment for your home or business. We’ll facilitate access to a reputable installer who can help you weigh up the pros and cons.

And you’ll get a free, no-obligation quote on installation cost, so you know exactly where you stand. We’ll also help you access the best heat pump grant available to you. Call us on 0330 470 1116 on contact us online.

Key Benefits of Air-to-Water Heat Pumps

Air-to-water heat pumps benefit both your pocket and the planet by lowering fuel bills and helping protect the environment. They also keep your property at a comfortable temperature all year round.

Reduced Heating Costs

Air-to-water heat pumps result in huge savings on energy bills, depending on the heating system they replace.

According to the Energy Saving Trust, switching to an air-to-water heat pump can achieve the following annual savings for an average-sized, three-bedroom semi-detached home (based on January 2024 fuel prices).

  • £1,100 if you currently heat your home with coal or old electric storage heaters.
  • £840 if you have newer electric storage heaters.
  • £510 if you have an old oil boiler or LPG (liquified petroleum gas) boiler.
  • £340 if you have an old gas boiler.

High Energy Efficiency

Air-to-water heat pumps take ambient air and convert it into a reliable source of heating. This green technology provides a low-carbon, highly efficient heating system, generating far more energy than the electricity it uses.

The air-to-water heat pump is playing a key role in decarbonising heating systems. It reduces carbon dioxide emissions by up to 2,800kg a year – the equivalent of using more than 1,000 litres of petrol. 

Optimal Temperature Control

Air-to-water heat pumps work best when left on all the time to regulate the temperature in your home or business premises. This will keep your building at a comfortable temperature throughout the changing seasons. 

  • In winter, the heat pump takes air from outside and compresses it to release heat inside.
  • In summer, it can do the opposite, transferring internal warm air to the outside.

Heating Upgrade Considerations

  • A regular air-to-water heat pump generates heat more slowly than a boiler and at a lower temperature. 
  • So you may need to think about making changes to your current heating system when you install a heat pump.
  • You may need larger radiators, for instance, or it could be a good time to switch to underfloor heating, which works well with an air-to-water heat pump. 
  • Either way, you’ll optimise the benefits of your heat pump if your property is well insulated.
  • High-temperature heat pumps provide a further option. These can produce temperatures of 60°C to 80°C, comparable to a gas boiler.

Heat Pump Grants

Various government-backed free funding to reduce the cost of an air-to-water heat pump is available for homeowners. 

  • Grants of up to £7,500 are on offer in England and Wales through the Boiler Upgrade Scheme (BUS).
  • The Energy Company Obligation Scheme (ECO4) provides financial aid for low-income households who want to switch to an air-to-water heat pump.
  • Other grants for households on low income include the Home Upgrade Grant (HUG), the Nest scheme in Wales, and Warmer Homes Scotland. 

Is an Air-to-Water Heat Pump Right for You?

All types of heat pumps can run on green energy, save money on heating bills, and produce minimal carbon dioxide emissions.The choice between an air-to-water heat pump and other kinds depends on various considerations.

An air-to-water heat pump is a good option if you want an energy-efficient system that not only heats your home or your business premises but also provides a hot water supply. Keep in mind that air-to-water heat pumps are primarily designed for heating, so they may be less efficient as a cooling system than an air-to-air heat pump.

An experienced heat pump installer can offer the expert advice you need to determine whether an air-to-water heat pump is right for your property. 

Find a heat pump specialist now.

Why Choose Heat Pumps UK?

Green energy specialist Heat Pumps UK provides a one-stop service that streamlines the whole process of arranging an air-to-water heat pump installation. As your single point of contact, we’ll help you access free heat pump funding, find a trusted installer, and arrange an inspection of your property. 

We’ve helped thousands of households and businesses get free funding through various government-backed heat pump initiatives, including the Boiler Upgrade Scheme and the Energy Company Obligation.

MCS-Certified Installers

Our partner heat pump installers are fully trained, and accredited and certified under the Microgeneration Certification Scheme (MCS). This quality assurance scheme for work on small-scale renewable energy systems guarantees your air-to-water heat pump will be installed to the highest standards.

Our heat pump engineers can typically install an air-to-water heat pump within a few days. And they provide a free aftercare service that optimises ongoing efficiency of the system and maximises savings.

No Obligation, No Hidden Charges

Heat Pumps UK is committed to making it easier and more affordable for homeowners and businesses to install heat pumps to reduce their carbon footprint and make big savings on energy bills.

Our air-to-water heat pump service places you under no obligation and there are no hidden charges. 

You don't need to be claiming benefits!

Find the best heat pump for your home.

Solar Assisted Heat Pump Price UK

Air-to-water heat pumps generally cost half as much as ground source heat pumps and pay for themselves in 5 to 10 years. Grants cut the cost of an air-to-water heat pump significantly. If you live in a smaller home, you could install a new heat pump for around £3,500 with a grant. In larger houses, the cost after a grant would be from £5,500 to £6,900. The government’s Heat and Buildings Strategy is expected to cut the cost of air-to-water heat pumps by 25 to 50% by 2025. In addition to grants, VAT on air-to-water heat pump installation is zero rated until March 31, 2027, when it will revert to the reduced rate of five per cent.
In most cases, you don’t need to apply for planning permission to install a heat pump. Planning consent is required if your property is a listed building, and it may be necessary if you live in a conservation area.
The main free funding towards air-to-water heat pump installation comes from the Boiler Upgrade Scheme and the Energy Company Obligation Scheme. Heat Pumps UK makes it easy to check your eligibility for a heat pump grant.

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Tony Renaud
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We had an Ideal Logic 2 Combi boiler fitted on 29/06/23 with Fixx. Craig the Engineer arrived bright and early after a call to say he would be there in 30 minutes. He was very efficient and finished by mid afternoon before running through all the wireless thermostat details before leaving. Found the company extremely helpful with any questions I asked, great company to do business with and would recommend highly.
Eduardo Benito
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Extremely impressed with Fixx and everyone there that I dealt with. They discussed all the requirements for a new under sink water heater for my flat to supply the kitchen sink and bathroom sink in the next room, as well as connections for a dishwasher and washing machinke. They provided a quote very quickly and the whole thing was installed just a few days later. Very neat setup, all ready for the kitchen fitter to complete the worktop and hook up the taps to the sink (see photos). I would 100% use Fixx again - I'm a very satisfied customer.
Simon Richards
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The two gentlemen from Fixx did a fabulous job removing my Boiler Mate 2000 and replacing it with an unvented cylinder. Everything at each stage was explained to me and they worked extremely hard to achieve a fantastic result. I won’t hesitate to contact them in the future if and when I need a new boiler and would 100% recommend Fixx to anyone.
Raluca Badea
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Very pleased with Fixx services, from start to finish. Craig kindly arranged for my Baxi Duo Tec boiler to be repaired asap and the engineer (Louis) arrived on time, was professional and polite, talked me through what he found and how he fixed it. Highly recommend! Thank you Fixx.
Phil Smith
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I've a contract for my boiler so when I found a leak, I contacted the helpline. Still had hot water but they still sent someone within 24 hours. Engineer (Darren) came and found the fault. Had the correct part in the van and heating was back on in around an hour from his arrival. Great service and knowledgeable. Highly recommend.
Ian Edwards
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Great service. Carl, the plumber, who sorted the boiler was so friendly and knowledgeable. So good in fact that we got the company to send him again to fit a Hive system which has helped us save a fortune.