Here’s what you need to know about getting an air source heat pump:

An air source heat pump is a renewable heating system designed to replace, or in some cases complement, your home’s traditional boiler. Invented in 1856, air source heat pumps have been in use for one and a half centuries to heat homes and supply hot water doing away with the need for fossil fuels. They’re especially popular in the Nordic countries, where temperatures often plummet below zero.

Air source heat pumps take advantage of the fact that outdoor air at any temperature above absolute zero (-273° Celsius) contains energy. It simply transfers a certain amount of this energy as heat from the outside to the inside of your home.

An air source heat pump does all the things your home’s boiler does only relying on the energy found in the air and some additional electricity instead of gas or oil as its primary fuel source. This means it’s much better for the environment – and often for your wallet, too.

An air source heat pump works much like a fridge in reverse.

An air source heat pump draws outside air into the system. This air is used to turn a refrigerant inside the unit into vapour. This vapour is compressed and produces heat as a result. The heat is then transferred to your home’s heating system, providing your home with heat and hot water. Air source heat pumps are designed to keep indoor spaces at a steady temperature with gentle top-ups through the day to keep you and your family comfortable.

The system is so efficient that heat can even be extracted from the air when temperatures fall below freezing. This ensures that even in the coldest conditions, your home’s heating won’t let you down while helping to lower your carbon footprint by up to 65% and reduce energy bills.

An air source heat pump is quieter than most people expect. In fact, government regulations dictate that heat pumps can only be installed if they do not exceed 42 decibels when measured from the closest habitable room (living room or bedroom). However, a heat pump will normally only operate at this level for a short time (while it is reaching the target temperature), and the volume will reduce thereafter. To put this into context, the humming of a fridge is around 40dB, and an average gas or oil boiler at home is somewhere around 50-55dB depending on model and age.

If the predicted noise level is greater than 42dB, you will need planning permission to install a heat pump at your property. Rest assured, our surveyors always conduct a sound check, prior to installation, to ensure the sound level is within the approved limit.

It is also worth mentioning that during the months that you are using your garden the most, your heating won’t need to be on so your heat pump will be silent.

To put the sound levels of an air source heat pump into perspective, see below how other ambient noises compare:

Noise levels

  • Breathing – 10dB
  • Bird calls – 40dB
  • Heat pump regulations – 42dB
  • Conversation at home – 50dB
  • Vacuum cleaner – 70dB

Increased heating efficiency– Air source heat pumps are up to 4 times more efficient than traditional boilers, and therefore require less energy to heat your home.

Reduced carbon footprint– Air source heat pumps don’t use fossil fuels and are better for the planet. Nearly 50% of the electricity on the grid now comes from low carbon sources – and your positive impact will be even greater if you are with a renewable energy supplier like Good Energy.

Lower fuel bills– Because air source heat pumps are much more efficient, they can cost a lot less to run. Homes that rely on oil, LPG or electric heating are most likely to make savings, while those on gas can achieve the same or even lower running costs. Find out more about cost savings in this article.

Smart energy control– Control your heating remotely with smart controls through your phone or computer and keep your heating system optimised to meet your heating needs as efficiently as possible.

Increased comfort– Keep your home at a steady temperature effortlessly with gentle automatic top-ups through the day to keep you and your family comfortable.

Long lifespan– The typical lifespan of an air source heat pump is up to 20 years.


Our air source heat pump installations are all covered by the following standards, giving you peace of mind about the quality of your new green heating system:

  • HIES
  • MCS
  • Trustmark
  • Gas Safe Register

Find out more about our quality standards for installing heat pumps here. 

Hybrid heating is a combination of your existing boiler and our highly efficient air source heat pump and smart controls. Combined, they create a heating system that uses less energy, costs less to run, and is better for the environment.

Depending on the outside temperature and your home’s heating capacity, our intelligent controls decide when to engage your heat pump or use your boiler. This ensures your home is always heated in the most cost-efficient way.

As your existing boiler provides your hot water requirements, hybrid heating can be a good option if you have no space for a hot water tank but want to save money on your energy bills. Please note though that hybrid heating setups are not eligible for the Government’s Boiler Upgrade Scheme Grant.

In a hybrid heating system, a heat pump is added to your existing heating setup to produce heat for the home. Your boiler is still used for hot water or to top-up the heat generated by your heat pump, for example on exceptionally cold days. The system makes use of the heat pump alongside your boiler to heat your home in the most efficient way. Combined, they create a heating system that uses less energy, costs less to run, and is better for the environment.

A hybrid system requires a functioning boiler but is likely to result in fewer changes to your current heating setup. Please note that hybrid systems are not supported by the government’s Boiler Upgrade Scheme.

In a standalone system your boiler is removed, and the heat pump powers your home’s heating and hot water. Standalone systems require a hot water tank, as the water must be stored once heated until it is ready to use. If you don’t have a hot water tank, this isn’t a problem as we can install one at the same time as your heat pump.

Air source heat pumps are extremely efficient at generating heat. In fact, they can produce up to four times more energy than the electricity they consume, making them 3-4 times more efficient than a standard boiler. This means you use much less energy for the same amount of heat, which is better for your finances as well as the environment.

The system is so efficient that heat can even be extracted from the air when temperatures fall below freezing. This ensures that even in the coldest conditions, your home’s heating won’t let you down while helping to lower your home’s carbon footprint by up to 65% and potentially reduce your energy bills.

The Boiler Upgrade Scheme (BUS) launched in April 2022 and will initially run for three years. The government has set aside £450m to provide grants of up to £7,500 to property owners to replace fossil fuel heating systems with air source heat pumps.

Contrary to the RHI, which paid owners of air source heat pumps quarterly over the course of 7 years for the renewable energy they produce after they’ve installed their heat pump, the BUS works differently. Interested parties will simply have to get a quote from an MCS-accredited installer, who in turn will apply for the voucher on behalf of the customer.

To be eligible for the BUS, the following requirements must be met:

  • Be a resident in England or Wales
  • Be a homeowner
  • The property must have an Energy Performance Certificate (EPC) that is not older than 10 years
  • The EPC must not recommend any of the following insulation measures
    • Loft insulation
    • Cavity wall insulation

Note that there are exemptions to these requirements, for example, in the case of listed buildings or those located in a conservation area.

If you have a valid EPC that recommends loft and/or cavity insulation but the measures have already been installed, you will have to get an updated EPC which evidences this.

Similarly, if you’re planning any works on your property such as an extension, these will have an impact on the heat requirements of the property. We recommend you complete these works first so that we can determine the heat loss of the property including any recent changes, which is essential in designing an efficient air source heat pump system.

There’s no hard and fast rule for how much electricity will be used by a heat pump, as it depends on the home it is heating and how warm you like your home to be. A proposal document by us will always include the estimated annual consumption of the new air source heat pump and a comparison against your current estimated usage so you know exactly what to expect.

The good news is that heat pumps are an incredibly efficient way to heat your home. Where a traditional boiler might operate at 90% efficiency, heat pumps can operate at up to 350%, meaning they generate nearly four times more energy than they consume.

When designed correctly, an air source heat pump easily maintains a constant and comfortable temperature in your home all year round – even in sub-zero weather. In fact, an air source heat pump can work effectively in extreme temperatures down to -15°C. Your heat pump will be designed, fitted and configured to work to the lowest temperature recorded in your postcode area over the last 10 years, as measured by the MET Office.

More than 1.4 million households in Norway comfortably rely on air source heat pumps as their source of heating despite the freezing temperatures of the Nordics. The efficiency will be impacted by colder weather but will always be higher than that of a standard boiler.

Inside your house very little will change. You’ll still have radiators and pipework, and you will also have a hot water tank. There are often a few more components on the hot water cylinder and a few zone valves, but nothing should feel too different. The main difference will be your heat pump unit outside your property.

When installing an air source heat pump, it has traditionally been standard practice to install a new ‘heat pump ready’ hot water cylinder – but in many instances it’s not the most practical solution as it presents homeowners with an additional cost that can sometimes prevent them from going green. We’re here to advise you about whether your existing hot water cylinder would be suitable for purpose.

The first thing to consider when looking at whether it is best to replace your hot water cylinder with a ‘heat pump ready’ one is the size of your existing cylinder coil. If your existing cylinder has a coil area of 2.5m² or more, it is already ‘heat pump ready’ and you do not need to replace it.

The impact of keeping your existing hot water cylinder is potentially higher running costs as it costs more to heat your hot water using the immersion than the heat pump, but on the positive side you would see an upfront saving of £2,000- £2,700 by not buying a new hot water cylinder.

Every house is different, and we will work with you to understand your existing setup and work out what the potential additional running costs and savings could be for you.

The size of your radiators impacts your heating system’s ability to heat your home to the desired temperature. Larger radiators, for example, allow the system to run at a lower flow temperature and create increased efficiency.

We may suggest replacing your radiators with larger models to increase the efficiency of your heating system. The advantages of larger radiators come from the larger surface area for heat to be transmitted to your room. Our surveyors will be able to confirm this as part of our survey and these replacements will be shown in your proposal document. For many of our installations, our surveyors found the existing radiators to be sufficient for the new air source heat pump to work at the highest efficiency levels.

If a pre-install survey concludes that some radiators would need upgrading, it’s important to note that these radiators rarely double in size. Rather think of it as replacing them with models that have an additional panel. Remember, it’s the surface area that counts, not the overall size of the radiator.

Our air source heat pump solutions are suitable for most homes, and our dedicated survey and design teams will be able to find the best option for your property.

A few things to consider:


  • The air source heat pump needs to sit outside the property on flat ground, ideally as close to your property as possible to increase the efficiency of the pipework. The size of the unit may vary slightly depending on the energy requirements of your properly. The smallest unit takes up a space of 0.4m³ and the largest one just 0.53m³ of space. By comparison, a standard 240 litre wheelie bin takes up 0.46m³.
  • It’s important for an air source heat pump to sit on a flat, stable surface outside of the property and that nothing blocks the air flow. We recommend having at least 30 cm of clearance to each side of the unit, 30cm to the rear of it, and 1.5m to the front. Our survey team will help with where to best position your heat pump.

Property type 

  • We can install in most properties. However, please note we are unable to install heat pumps in flats/ maisonettes /apartments and non-domestic properties.
  • Listed buildings are not always restricted and many owners of listed buildings are able to install heat pumps. We’d advise you to first check with your local planning authority for their specific guidance before proceeding.
  • For homes in conservation areas or heritage sites, it is often still possible to install a heat pump. However, we’d advise you to first check with your local planning authority for their specific guidance before proceeding.

Solar panels can work well with a heat pump. The solar panels will create the electricity for the heat pump to run on, essentially providing your own cycle of renewable energy, ideal for when you’re looking to reduce your carbon footprint even further. Our surveying team will be able to discuss this with you during a survey of your property.

Yes, underfloor heating works well with our systems. Air source heat pumps emit a continuous flow of heat (around 40°C), which is exactly what underfloor heating needs. This makes underfloor heating and air source heat pumps a great combination.

If you’re currently on a full electric system, we would need to install an entirely new “wet” central heating system including radiators and pipework, to be able to install our air source heat pump. If you already have a “wet” heating system powered by a fully electric boiler, your heating can easily be converted to run on a heat pump, and you could make significant savings on your heating bills.

A heat pump requires higher water flow rates than a traditional gas or oil boiler, and as ‘microbore’ pipework is usually 8-10 mm in diameter (about the thickness of a ball point pen), this is simply too narrow to handle the flow rates needed. Therefore ‘microbore’ pipework isn’t compatible with a heat pump and would need replacing with larger diameter pipes (usually 15 mm and 22 mm) for us to install your new heat pump.

This is something we will identify and manage on your behalf.

Any changes made to the structure of your home are likely to impact its heat requirements and therefore the system design. If you are planning any renovations that will change the shape, size, or floor plan of your house, it is worth having the plans completed before getting a heat pump. You will also need to consider getting an update to your EPC (Energy Performance Certificate).

We will need to understand how the system will work in the new house design to ensure it’s right for your home. Having your heat pump installed before the works are completed may risk the system not functioning correctly.

Small changes, for example redecorating or installing a new bathroom suite, will not impact the heat demand of your house, so if you are only planning these sorts of changes we can proceed as normal.

Underfloor heating works well with a heat pump. However, having it fitted after your heat pump has been installed would still constitute a change to the heat demand of the system, so risks the system not working at maximum efficiency.

To get the most out of your underfloor heating and heat pump combination, it’s best to have this designed as a single system so it can work at maximum efficiency. We would therefore need to know all the details upfront. Let us know if you are planning a change to underfloor heating and we can ensure this considered in your heat pump system design.

Insulation requirements for Boiler Upgrade Scheme (BUS) 

To be eligible for £5,000 BUS grant, the following requirements must be met:

  • Be a resident in England or Wales
  • Be a homeowner
  • The property must have an Energy Performance Certificate (EPC) that is not older than 10 years and which has a heat demand number stated on it
  • The EPC must not recommend any of the following insulation measures
    • Loft insulation
    • Cavity wall insulation

There are exemptions to this requirement in the case of listed buildings or those located in a conservation area. In these cases, it’s best to check with your local planning authority to get specific advice for your home.

We always recommend having your insulation work completed prior to having your heat pump system designed. This is because we design to the current heating requirements of your home. Having insulation installed at a later point will change the heating demand (by reducing the heat loss and therefore making your home more efficient), so you may end up with an oversized (and possibly more expensive) heat pump if you haven’t completed the insulation beforehand.

Your Energy Performance Certificate (EPC) will contain information about your property’s energy use and suggestions on how to make the property more efficient.

Virtual surveys 

Our experts can assess your home over a video call to determine the best solution for your home.

Home visit surveys and installations 

We also offer home visit surveys. Get in touch with us on works@goodenergy.co.uk and we will help you to identify which option would be best for you.

Every install is different, so there’s no one-size-fits-all answer. Once you’re happy with the design for your property, and have agreed an install date with our team, we’ll provide you with a personalised timeline for your installation.

Before we carry out your installation, we’ll take care of all the preparation behind the scenes and order everything to the requirements of your design. Once our team are on site, they’ll explain the installation process and keep you updated on progress.

If we anticipate any disruption to your heating or hot water, we’ll let you know in advance so there aren’t any unexpected surprises. Our installation team are professional, highly trained and qualified – so if you have any questions while they’re working, they’ll be more than happy to answer them.

Here are the dimensions for a typical air source heat pump – even the largest one is smaller than a standard wheelie bin. The more powerful heat pumps are the largest; and these are suited to larger homes or ones that lose heat more easily:

  • 5kW unit: HWD 88cm x 79cm x 31cm
  • 8kW unit: HWD 94cm x 99cm x 33cm
  • 12kW & 16kW unit: HWD 94cm x 142cm x 33cm

Your installer will be able to identify the most suitable location and the most appropriate size of unit for your home, which should all be explained prior to install. It will need to be placed in a location with good airflow that is easily accessible for maintenance. This often means on the ground at the rear of the property, although they can also be hung to the outside wall of your home.

We don’t currently offer a heat pump tariff although this is something we might offer in the future. Please check our tariff information page soon, or join our newsletter to hear about any new product launches.

There is a 10-year manufacturer’s warranty on the heat pump and a 2-year workmanship warranty as we are a member of the consumer protection scheme HIES. HIES offers customer advice and protection following the installation of renewable energy systems.

More information on the warranty can be found in your handover pack after your install is completed.

There is no scheme to elongate the life of a warranty, but your heat pump will require yearly servicing to ensure the warranty remains valid for those 10 years, just like a regular boiler. Once the warranty ends, it is recommended to continue good maintenance and regular servicing to prolong the life of your heat pump.