High-temperature heat pumps are becoming recognised as a highly effective low-carbon solution for heating homes in the 21st century, playing a critical role in the UK’s journey toward net zero by 2050 and fostering a more eco-friendly nation.

While low-temperature heat pumps can adequately heat most homes, they typically require the installation of larger radiators or further insulation to achieve conventional temperatures of 45 degrees Celsius or less.

In contrast, high-temperature heat pumps can reach higher temperatures comparable to those produced by gas and oil boilers, and they can operate with existing home heating systems without necessitating modifications.

The Committee for Climate Change has pinpointed high-temperature heat pumps as a practical alternative for numerous households where low-temperature models fall short.

These pumps can efficiently heat using existing radiators with minimal to no adjustments needed.

This capability is especially significant given the UK government’s target of 600,000 heat pump installations per year by 2028, supported by substantial government funding and grants.

Currently, high-temperature heat pumps demonstrate an impressive 16% to 25% increase in efficiency over traditional heat pumps. They boast average seasonal efficiency ratings ranging from 3.5 to 5.0, versus 3.0 to 4.0 for their standard counterparts.

This superior efficiency not only helps achieve the UK’s ambitious mid-century net zero target but also reduces household energy bills and overall energy costs in the long term.

In this guide, we explore the myriad benefits and ongoing developments in high-temperature heat pump technology, illuminating how these systems offer a viable and efficient option for enhancing sustainability in home heating.

High-Temperature Heat Pump Key Points:

Cost Range: Installation costs vary from £5,000 to £40,000, covering labour and supplies.
Efficiency: High-temperature heat pumps offer efficiency ratings between 350% and 500%, notably more efficient than standard heat pumps.
Price Comparison: On average, these pumps are not significantly more expensive than normal heat pumps, though prices can differ by product and brand.
Selection Criteria: Consider energy efficiency ratings, installation space, and budget. Allow for potential additional expenses.
Home Compatibility: Unlike low-temperature pumps, high-temperature pumps can utilise existing radiators without costly upgrades, as recognised by the Committee for Climate Change.
Government Incentives: Regional grants, funding, and loans in the UK can reduce installation costs by £7,500 to £9,000, supporting the transition to renewable energy.

What Are High-Temperature Heat Pumps?

High-temperature heat pumps are a type of energy device that extract heat from the surrounding environment to warm homes.

They can utilise air or tap into the Earth’s thermal energy using ground source technology.

Key characteristics of high-temperature heat pumps include:

Temperature Output: These pumps are capable of producing temperatures of 65 degrees Celsius and above, with some models reaching up to 80°C.
Efficiency and Comparison: While standard heat pumps are improving, achieving temperatures around 60-65°C with enhanced efficiency, high-temperature heat pumps generally provide superior performance.
Suitability for Certain Properties: Due to their high output temperature, these pumps are particularly well-suited for properties prone to significant heat loss, such as older or larger buildings, and those that are not connected to the gas grid.
Ideal for Specific Needs: They are most beneficial in homes that are off the gas grid or currently use oil boilers, which are costlier and less environmentally friendly than natural gas boilers.
Versatility: Although especially effective for homes with significant heat loss issues, high-temperature heat pumps are adaptable to a wide range of property types.
Climate Compatibility: In colder regions like the UK, these heat pumps ensure homes remain warm and comfortable throughout the harsh winters.
Cost-Effectiveness: High-temperature heat pumps are much more efficient than traditional gas boilers, resulting in lower operational costs and enhanced heating capabilities.

Overall, high-temperature heat pumps offer a robust, eco-friendly heating solution that can address heat loss issues and potentially lower heating bills, making them an attractive option for diverse properties across the UK.

Benefits of High-Temperature Heat Pumps

High-temperature heat pumps offer several standout benefits, making them an attractive alternative to traditional gas boilers in suitable properties.

Here’s a detailed look at these advantages:

Energy Efficiency and Cost Savings

High-temperature heat pumps are significantly more efficient than gas boilers.

According to manufacturers like Viessmann and Daikin, these pumps can achieve efficiencies between three and five times higher than those of gas boilers, whereas regular heat pumps typically range from 1.5 to 3 times the efficiency of gas boilers.

This higher efficiency means that despite higher electricity prices, high-temperature heat pumps can often be a more cost-effective heating option.

Running Costs

Current energy pricing under the UK’s direct debit cap lists gas at approximately £0.07 per kWh and electricity at around £0.27 per kWh, though these rates can vary based on payment methods and suppliers.

High-temperature heat pumps with a Seasonal Coefficient of Performance (SCOP) of 4.0 to 5.0 are generally less expensive to operate than gas boilers when considering the total cost of energy consumed.

Property Suitability

High-temperature heat pumps are particularly beneficial for older buildings or those lacking in insulation, where they can significantly enhance heating efficiency.

These pumps are often recommended for properties prone to heat loss, such as historic or listed buildings.

Long-Term Considerations

While high-temperature heat pumps do not replace the benefits of good insulation, they can serve as a cost-effective interim solution while planning for more comprehensive energy-saving measures.

Although the global energy landscape is subject to fluctuations and the future costs of energy sources cannot be predicted with certainty, the efficiency of high-temperature heat pumps may position them as a more advantageous option in the long run compared to gas boilers.

Overall, high-temperature heat pumps not only offer a greener alternative to fossil fuel-based heating but also present a financially sound choice for homeowners, especially in properties where traditional heating solutions fall short.

The evolving energy market and potential long-term decreases in electricity costs could further enhance the appeal of these systems.

Environmental Benefits

How eco-friendly a high-temperature heat pump is will depend on the specific installation and where the electricity needed to run it is sourced.

As discussed, high-temperature heat pumps offer about 3x to 5x the efficiency of gas boilers.

Despite this, we still need to consider any fossil fuels burned to produce the electricity on the national grid that is used to power the heat pump.

The good news is that according to a government energy plan from March 2023, about 40% of the UK’s electricity is sourced from renewable sources whereas 15% comes from nuclear power.

This combined with the efficiency of high-temperature heat pumps makes a strong case for them being more eco-friendly than gas boilers, even if costlier to run.

Also, you can ensure that your high-temperature heat pump is more environmentally friendly and even zero carbon if you source electricity from a green energy provider.

Alternatively, using an on-site source of renewable energy (e.g. a suitably sized solar panels array) can act as a carbon-free way of running a high-temperature heat pump.

That said, many of the more powerful high-temperature heat pumps may require too much electricity for a realistic solar system setup to prove sufficient.

Compatibility with Existing Radiators and Heating Systems in the UK

You may be able to use a high-temperature heat pump with existing radiators, however, in some cases, larger radiators may be needed.

For most heat pumps, they’ll need a relatively large heating output source (e.g. larger radiators or underfloor heating).

However, since high-temperature heat pumps do not come with the same low heating output as regular heat pumps, this may not apply.

Since each high temperature heat pump will have its own heat output temperature, it’s best to discuss this with your installer in advance.

That way you can determine whether sticking with your existing radiators is sufficient or if an alternative may be needed.

Having a high-temperature heat pump may be more suited to an old property than a regular heat pump as the latter is more likely to include upgrading your radiators or having underfloor heating added too.

Therefore, a high-temperature heat pump instalment may save money and prevent plenty of hassle as an alternative to a regular heat pump, particularly for older homes.

When it comes to heat pumps in general, while opting for larger radiators can do the job (when a larger surface area is needed), underfloor heating tends to be more cost-efficient.

According to UK underfloor heating company Nu-Heat, a heat pump-underfloor heating setup can be as much as 40% more efficient than a heat pump-radiator approach.

That said, in this scenario, the upfront cost must be taken into account and the fact that this setup may or may not pay for itself with time depends on how running costs evolve over time.

All in all, there is no straightforward answer as it comes down to a case-by-case basis. That way, ensuring you know what the best options are for an installation you have in mind is important to minimise any negative outcomes.

Factors to Consider When Choosing a High-Temperature Heat Pump

Getting the right high-temperature heat pump for your home is key to ensuring that you get the most from what will, one way or another, be at least a several thousand-pound installation.

There are many measures that can determine the suitability and advantages of different high-temperature heat pumps.

Of course, the more advantageous a heat pump is, the more expensive it will likely be. Therefore, if you have a limited budget, a certain degree of tradeoff may be necessary.

Energy Efficiency Ratings

Firstly, you’ll want to consider how efficient you’d like your high-temperature heat pump to be.

You can determine this using measurements such as Coefficient of Performance (COP) and Seasonal Coefficient of Performance (SCOP). The latter is a more accurate measure of average efficiency over time.

For example, Viessmann states that their Vitocal 300 range (comprising several high-temperature ground source heat pumps) comes with a COP of up to 4.2 to 5.0. According to the Heat Pump Warehouse, LG’s Therma V 16kW R32 High-Temperature Split Outdoor Unit offers a COP of up to 4.9.

If you have an old/or inefficient property with poor insulation, you’ll want to especially pay attention to keeping performance stats such as energy efficiency or temperature output capacity.

Discuss with your installer if unsure as to what sort of energy efficiency rating will make the most sense for your home without exceeding your budget.

Temperature Output Capacity

A relatively high output capacity also reflects how successful a high-temperature heat pump can be at keeping bills down and heating your home fast and effectively.

Many of the top high-temperature heat pumps on the market provide maximum temperature outputs of between 70°C and 80°C.

Rated Output

The rated output of a high-temperature heat pump measures its power. This way, buyers can get a sense of how well any given unit will perform.

High-temperature heat pumps generally offer output ranges of between 16kW and 45kW.

However, exceptions to the rule include Viessmann’s incredible Vitocal 350-G Pro high-temperature heat pump known for offering an output of 27.3kW to 197.9kW.

This is important to consider the overall quality of varying heat pumps. For example, one heat pump may have a higher temperature output capacity than another.

However, if the latter has a higher rated output and offers more efficiency it may do a better job overall. If in doubt, you can always discuss these details with your installer or/or the manufacturer ahead of making a decision.

Space Requirements

The primary heat pump unit will likely only use up around 0.5m² to 1.5m² of space. However, the infrastructure required beyond that can use up much more space.

While both ground and air-source heat pumps will use up plenty of space, ground-source heat pumps generally use up more.

With that said, even if you have a small to mid-sized garden space, most of a ground source heat pump’s infrastructure can often be installed vertically, going underground.

This can allow high-temperature ground source heat pumps to be added where a horizontal installation is impossible.

In total, a ground source heat pump may need around 200 to 300 square metres of land to install pipework.

The use of boreholes (being drilled to as far as 100 metres below the ground) can allow for an effective vertical installation.

Alternative Options

While a high-temperature heat pump can be installed in most properties, some will benefit more from it than others.

Therefore, for a range of reasons (including your budget), you may find that a regular heat pump does the job. If you have a new property with high levels of insulation, an ordinary heat pump may make the most sense.

That said, high-temperature heat pumps tend not to be much more expensive than ordinary heat pumps. It’s more a matter of how every penny and attribute of one option or another can add up, particularly if you’re on a tight budget or/or you have very specific requirements.

Older housing stock will usually find that a high temperature is the most suited option. Another choice worth considering, however, is a hybrid heat pump system.

This involves having a heat pump installed but continuing to use your existing heating system (if suitable for a hybrid system – e.g. a gas boiler).

A combined system like the one mentioned above can allow you to get the best of both worlds while potentially keeping your upfront costs down.

With that being said, government funding may not cover a hybrid heat pump instalment. For instance, the Boiler Upgrade Scheme or BUS does not cover hybrid heat pump systems.

If unsure about what the case is in your region or in relation to any localised funding, check with your local council to find out if funding might cover a high-temperature heat pump and whether or not you are eligible.

Your Budget

According to a range of online stores (including Orion Air Sales, Cool Energy Shop and MeinHaus Shop), high-temperature heat pumps generally cost somewhere in the region of £4,000 to £21,000 in supply cost.

The price of labour will add at least several thousand pounds more to the total.

By knowing how much you’re willing to spend, you’ll get an idea of what high-temperature heat pumps are within your budget.

It’s important to have some leeway as the total price may end up higher than initially quoted for a range of reasons.

It’s worth noting that government funding exists for eligible households to apply for. For more information, see the ‘Government Incentives and Funding’ section towards the end of this article.

Long-Term Maintenance

Heat pump manufacturer Daikin advises that heat pumps are serviced by a qualified engineer annually.

An annual servicing will probably cost around £200 to £400 but potentially more where repairs or/and maintenance work is needed.

Various plans exist, so seeking one that provides good value for money is one way to keep servicing and maintenance costs down over time.

Considering a high-temperature heat pump will likely last for around 20 to 30 years, it’s possible that long-term maintenance will cost £10,000s over a two to three-decade timeframe.

However, such costs may come down with time, possibly making the cost of maintaining an average high-temperature heat pump less than £10,000 over its lifespan.

Best High-Temperature Heat Pumps in the UK

Only a few high-temperature heat pumps are currently available on the UK market, although more may arrive in the near future.

In total, five ranges are currently available on the UK market.

In 2024, here are the best temperature heat pumps that can be purchased in the UK:

Brand	Heat Pump Model	Key Features	SCOP Rating	Price Range*
Daikin	ETBH Altherma 3 H HT Indoor Unit 14kW to 18kW	High-Quality Casing, Three-Layer Insulation, And Bizone Settings	3.58 to 4.81	£4,000 to £6,300
Trianco	Activair High Temperature Heat Pump 9kW to 22kW	Anti-Frost Protection, Wi-Fi Immersion Control, And Relatively Lightweight	-N/A	£4,080 to £6,240
Vaillant	Arotherm Plus	Can Operate In Extreme Frost And Temps Of Up To 75°C	Up to 5.03	£3,400 to £6,500
Samsung	HT Quiet (HTQ)	Very Low Sound Levels, Hybrid Capacity	3.53 to 4.68	£3,900 to £5,600

*This refers to the supply costs only. The price of labour will generally add a minimum of several thousand pounds to the total.

Daikin’s ETBH Altherma 3 H HT Indoor Unit range is well-suited to a wide range of properties.

Beyond that, these high-temperature heat pumps come with sound outputs of 35-38 dBa. In general, ground source heat pumps can generate up to 42 dB.

It can also deliver temperatures of up to 70°C thanks to a special, hi-tech compressor. Its zone settings may also be used to heat two different areas of your home with different temperatures if practically possible.

As for the Trianco Activair High-Temperature Heat Pump range, this comes with anti-frost protection, a range of siting options, a plastic weatherproofing case, mounting places that can be used for a wall or floor and a pre-plumbed heat pump cylinder.

Installation and Maintenance

It’s important to know what is involved in having a high-temperature heat pump, as well as the maintenance needed over time to prolong its lifespan. Proper maintenance (and done by professionals)

Having a High Temperature Heat Pump Installed

To have a high-temperature heat pump installed, you must hire an engineer who is qualified for the job.

This will involve securing a quote from one (or several) engineers who can install high-temperature heat pumps. Landing various quotes can help you make an informed choice, making it more likely that you’ll get good value for money.

How to Maintain a High-Temperature Heat Pump

Once installed, it’s important that your high temperature heat pump is maintained properly. Along with having your heat pump serviced annually and maintained/repaired when needed, there are steps you can take too.

By following the manufacturer’s instructions (and checking whether or not this is suitable for your high-temperature heat pump in particular), you may want to rid the outside of the unit of debris such as leaves.

Just be careful not to get your hands or equipment too close to the unit, even with the protections in place.

Along with using a soft brush to carefully sweep away debris, you’ll want to make sure that tree or bush growth is not growing too close to the heat pump.

For instance, the branches of a nearby tree may, over time, begin to overhang the unit, therefore safely trimming these branches or removing them as needed can help prevent issues arising.

Beyond that, other forms of maintenance (e.g. refilling a refrigerant) must be done by professionals.

Ensuring that your heat pump is serviced at least once a year and that any issues that arise are looked at quickly can help maintain it well and keep the unit going for longer.

Other Tips for Long-Term Efficiency

Along with the ideas discussed already, here are some further tips to consider for the long-term efficiency of a high-temperature heat pump:

Ensure any damage is addressed promptly and do not let the heat pump run if it is damaged or you otherwise have concerns over its functioning
Using optimal settings per the manufacturer’s instructions
Consider improving how well your home is insulated so that you won’t need to run your heat pump as often as you would otherwise*

*This is preferable because running your heat pump less can help it last longer due to a slower accumulation of wear and tear. This, in turn, can maintain your heat pump’s efficiency.

Important Note: If your heat pump turns off or it is necessary due to safety concerns but you’re worried due to the heat loss (e.g. someone in your home is vulnerable and lack of heating may be dangerous), take all safety precautions such as non-central heating means of warming up.

This might include simply adding more layers or getting under the blanket. Beyond that, you can call an emergency engineer, the manufacturer or if deemed necessary, the local authorities.

Safety should come first both in terms of the operation of your heat pump and the safety and well-being of everyone on the property.

Government Incentives and Schemes

You’ll be pleased to know that government funding is available for eligible homes through the Boiler Upgrade Scheme (BUS). This scheme supports households in England and Wales aiming to lower their carbon footprint.

Via the BUS, properties with a successful application can have the total cost of installation slashed by £7,500 regardless of the type of high-temperature heat pump. That said, hybrid heat pump systems (e.g. a system featuring a heat pump and gas boiler) are not eligible.

To apply, you’ll need to contact the installer you want to fit your high-temperature heat pump and ask them to check your eligibility for you. They can apply on your behalf before agreeing on a final quote, with the BUS reduction factored in too.

Eligible households in Scotland can benefit from a heat pump grant of between £7,500 and £9,000. Securing a several thousand pounds loan may also be possible.

Among the eligibility requirements for a Home Energy Scotland Grant include that you live in your home and the proposed installer is part of the Trading Standards Institute accredited consumer code related to energy storage.

Ultimately, it is likely easier to prove eligible for this grant than is the case for English and Welsh households when it comes to the BUS grant.

If you’re looking to apply for a grant or/loan in Scotland, you can do so via Home Energy Scotland’s official website. The steps involved in applying include completing a Home Energy Check and looking into your home’s Energy Performance Certificate (EPC) if applicable.

Beyond that (and especially if your home is not eligible for a BUS grant), it’s worth contacting your local council to see if any other funding exists in your region. If other funding exists, you should inquire about the eligibility requirements and how to apply.

Whatever grant, funding or loan you’re looking to apply for, be sure to take your time to confirm what is needed and (if eligible) your application is submitted fully and correctly. This can avoid unnecessary hassle down the line.

High Temperature Heat Pumps Conclusion

Having a high-temperature heat pump added to your home may not be a low-cost option (generally ranging from £5,000 to £40,000 in total) but it can provide a wide range of benefits.

To make the most of a high-temperature heat pump, be sure to opt for a suitable option for your home.

It’s also a good idea to get quotes from several qualified installers/services. This can help you make an informed choice when deciding who to hire.

Here is what you’ll need to consider and factor into your thinking regarding a high-temperature heat pump installation:

Hiring the right person/company for the job
Getting a detailed quote that shows how much the work should take
Confirm (again with a professional) whether your property makes a high-temperature installation possible to begin with
Think about your budget and whether (with some leeway too), a high-temperature heat pump installation is affordable
Look into any suitable funding, grants or/interest-free loans and see whether your household is eligible
Find out (through a professional) whether or not larger radiators or/or underfloor heating are needed or even just preferable
Consider and discuss potential added costs or unexpected fees that may apply
Along with the cost of a high-temperature heat pump, you’ll want to focus on its performance details (e.g. energy efficiency rating and temperature output capacity)
Think about potential maintenance costs and the longevity of the high-temperature heat pumps you have in mind and any guarantees or warranties, among other key considerations

A high-temperature heat pump added to your home can act as a viable replacement for a gas boiler with the potential to lower energy bills and your carbon footprint.

High-temperature heat pumps are arguably, more eco-friendly on the whole. This is especially true if it’s powered by green energy, whether from a supplier or on-site renewable technology like solar panels.