How does a heat pump work?

If you’ve ever used a fridge, you’ve already experienced heat pump technology,  just in reverse! A heat pump is a highly efficient system that captures heat from the air or the ground outside your home and uses it to warm the inside. It’s low-carbon, low-maintenance, and cleverly cost-effective over time.

Instead of burning fuel to create heat (like gas boilers do), a heat pump moves heat from one place to another, even in cold weather. They can function at temperatures as low as -15 degrees.

The heat pump absorbs heat from the outside air or ground and transfers it to a liquid in the heat pump called a refrigerant. Having a low boiling point means this refrigerant will boil easily; it can then be compressed, which increases the temperature further. The now gaseous refrigerant passes through a heat exchanger, which allows this energy to be transferred into water, and taken into your home through your radiators, underfloor heating, and hot water cylinder. As it moves heat rather than generates it, a heat pump can deliver 3–4 times more energy than it consumes in electricity, making it one of the most energy-efficient systems available.

Benefits of switching to a heat pump

Heating isn’t just another utility; it’s the beating heart of a comfortable home. Whether you’re battling chilly Scottish winters or trying to stay on top of rising energy costs, the way we heat our homes has never mattered more.

Traditional heating systems like gas and oil boilers are becoming outdated, costly to run, reliant on fossil fuels, and increasingly at odds with the UK’s drive towards being carbon neutral. In contrast, heat pumps offer a forward-thinking, environmentally responsible alternative that’s already transforming homes across Scotland.

By switching to a heat pump, you’re not only reducing your carbon footprint, but you’re unlocking a more efficient, reliable, and cost-effective way to heat your home. And with generous government support available through the Home Energy Scotland Grant, the transition is more accessible than ever.

So, what makes heat pumps such a smart investment? Let’s explore the top benefits for your wallet, your comfort, and the planet.

Year-Round Comfort

One of the greatest benefits of a heat pump is the consistent, year-round comfort it brings to your home. Unlike traditional systems that blast heat in short bursts, a heat pump delivers a steady, gentle warmth that keeps every room at just the right temperature, even on the coldest Scottish mornings.

It works quietly in the background, maintaining your chosen comfort level without the peaks and troughs of older heating systems. Paired with good insulation and smart controls, it creates a more balanced, cosy and energy-efficient home environment, whatever the season.

Lower Running Costs

Heat pumps are incredibly efficient. They don’t burn fuel to create heat, but instead move existing heat from the air or ground. For every unit of electricity used, they can generate up to three or four units of heat. This can translate into significant savings on your energy bills, especially if you're currently using oil, LPG, or electric heating.

Cut Your Carbon Footprint

Traditional gas and oil boilers are major contributors to household carbon emissions. A heat pump can reduce your home’s carbon footprint by up to 65%, depending on the system it replaces, making it one of the most impactful ways to decarbonise your home.

Government Support

Households in England and Wales can access £7,500 in grant funding towards the cost of a heat pump via the Boiler Upgrade Scheme.

If you live in Scotland, you could access up to £7,500 in grant funding (or £9,000 if you qualify for rural uplift) through the Home Energy Scotland Grant to help cover the cost of installing a heat pump. An optional interest-free loan is also available to top up the difference, making the investment far more manageable and attractive.

Low Maintenance, Long Life

When properly installed, a heat pump runs efficiently without the frequent adjustments or fine-tuning that traditional boilers often require.

Add Value to Your Home

With growing demand for energy-efficient properties, installing a heat pump can enhance your EPC rating, for example, by installing a heat pump, solar, and having a battery, which will take you to an A EPC-rated home. As a result, this can give you access to potentially better mortgage offers, and it appeals to eco-conscious buyers, boosting your home’s long-term value.

Switching to a heat pump is about more than just heating, it’s about taking control of your energy future, lowering your bills, and making a lasting difference for your home and the planet.

How much does a heat pump cost and save?

Installing a heat pump is an investment, not just in your property, but in lower energy bills and a more sustainable future. While the upfront cost can seem significant, generous Government support and long-term savings make it a far more affordable choice than many homeowners first expect. The typical installation cost of a heat pump can vary depending on your home’s size, type, and the setup of your current heating system.

If your home is already reasonably efficient, and your current radiators, pipework, and hot water tank are suitable, you may be able to install a heat pump without upgrading the rest of your heating system.

A typical air source heat pump-only installation costs between £7,000 and £10,000, and includes:

• The heat pump unit.
• Outdoor and indoor components (e.g. pumps, valves, controls).
• A heat pump-compatible hot water cylinder.
• Smart controls or weather compensating controls.
• Full system design and professional commissioning.
• MCS certification (which is essential for claiming government grants)

If you’re in England or Wales, you can apply for up to £7,500 through the Boiler Upgrade Scheme (BUS). The grant is paid directly to your installer, reducing your upfront cost, often bringing your total outlay to around £1,000–£3,000, depending on your home and system choice.

If you’re in Scotland, you can apply for up to £7,500 through the Home Energy Scotland Grant, or £9,000 if you qualify for the rural uplift. In some cases, you may also be eligible for an optional interest-free loan to cover the remaining cost.

If you’re in Northern Ireland, grants are available through the Northern Ireland Sustainable Energy Programme (NISEP) and other local schemes. These vary by provider and region, but typically offer partial funding for systems, with priority given to lower-income households.

How Much Does It Cost to Upgrade Your Heating System Too?

For many homes, especially those with older radiators, pipework, or a combi boiler, it’s worth upgrading the rest of the heating system at the same time to maximise performance and savings.

Here’s what might be included in a full heating system upgrade:

• Larger or more efficient radiators
• A new, well-insulated hot water tank
• Pipework upgrades (if needed)
• Smart zoning and controls
• Buffer tank or thermal store (in larger or more complex homes)

This type of project typically costs between £12,000 and £18,000, depending on your home’s size and complexity. Across the UK, government grants such as the Boiler Upgrade Scheme in England and Wales, the Home Energy Scotland Grant, and regional schemes in Northern Ireland can cover up to £7,500–£9,000 of that cost. That means many homeowners end up paying around £5,000–£9,000 for a fully modernised, low-carbon heating system.

A ground source heat pump installation ranges from £20,000 to £35,000 due to the groundwork and borehole required.

The cost of installing a heat pump isn’t just for the unit itself. It also includes professional design, labour, and system upgrades to make sure everything runs efficiently in your home.

While these figures may seem high at first glance, they don’t tell the full story, because generous government support is available to make heat pumps more affordable. The Home Energy Scotland Grant, along with the rural uplift scheme, can significantly reduce what you pay, covering up to £7,500–£9,000 of your installation cost. And it's not just a like-for-like swap. As part of the upgrade, we’ll convert your hot water system to mains pressure, giving you powerful, invigorating showers and improved water flow throughout your home.

At the same time, we’ll reset and optimise your heating system to operate efficiently at lower temperatures, ensuring your home stays warm, comfortable, and energy-efficient, all year round. It’s a complete heating transformation that delivers both immediate comfort and long-term savings.

Why You Don’t Need to Do It All at Once

At Warmur, we understand that every home is different, and every homeowner is on their own journey. That’s why we don’t just drop in a heat pump and disappear.

We take a phased approach that fits your home, your budget, and your lifestyle. We can start by installing a heat pump that works with your existing radiators and run it at slightly higher temperatures, helping you start saving money and cutting carbon immediately.

Then, when the time is right, we can help you:

Upgrade your heating system for even greater efficiency

• Add solar panels to generate your own electricity
• Install a battery to store energy and become less reliant on the grid
• Access the best tariffs for low-cost, off-peak energy
• Optimise your system with smart controls and ongoing performance monitoring.

With Warmur, you’ll always know your next best move, a clear plan that makes every upgrade smarter, not harder.

Running costs versus gas or oil, and what you could save

One of the biggest long-term advantages of a heat pump is its outstanding efficiency. While traditional boilers burn fuel to generate heat, heat pumps simply move heat using electricity to transfer warmth from the air or ground into your home. That means for every 1 unit of electricity used, a heat pump can deliver 3 to 4 units of heat, significantly lowering your energy consumption.

Typical Annual Running Costs

Here’s how average running costs for heating and hot water compare across different systems in a well-insulated Scottish home (based on fuel prices as of early 2025):

Heating Type Annual Running Cost

• Mains Gas  £1,000 – £1,400
• Oil £1,500 – £2,000
• LPG £1,700 – £2,300
• Electric (direct) £2,000 – £2,500
• Air Source Heat Pump £900 – £1,300
• Ground Source Heat Pump £800 – £1,100

These figures will vary depending on your tariff, which can reduce the running costs by another 25%. It also varies depending on the size of your home, your insulation, heating habits, and if you combine it with our renewable energy technologies, such as solar and a battery. However, in many cases, heat pumps can reduce your heating costs by 30–50%, particularly if you’re switching from oil, LPG, or electric.

What’s involved in the installation and why it affects the cost

The cost of installing a heat pump isn’t just for the unit itself; it also includes professional design, documentation, labour, and system upgrades to make sure everything runs efficiently in your home.

Here’s a breakdown of what the installation typically involves:

1. Initial Home Survey & Heat Loss Assessment

At Warmur we offer a Home Energy Passport, which gives you a detailed 3D walk-through model of your home that captures all the information an installer would need to give you a detailed, complete quote, including price, no matter how complex the job is. Whether you're looking to cut your carbon footprint, lower bills, or future-proof your property, your Passport is what you need to get the best quote for your home heating upgrade.

From that passport, we can do a detailed heat loss calculation of your property to determine the right size of heat pump for your home and identify any upgrades needed (e.g., insulation or radiator changes). This step is essential for both performance and eligibility for government funding.

2. System Design & Specification

The installer will design a bespoke heating system tailored to your property. This includes choosing the right type and size of heat pump, the correct cylinder for hot water storage, and the best layout for pipework and controls.

3. Internal Upgrades

In many homes, especially older ones, your existing radiators may be replaced with larger, low-temperature models to work effectively with a heat pump. In some cases, you may need to install or upgrade a hot water cylinder, and allow space indoors for control units or water tanks.

4. Outdoor Unit Installation

For air source heat pumps, the main unit is installed outside, typically on a concrete base near a wall. It must have good airflow and meet permitted development rules (or planning permission in some cases, such as listed buildings).

For ground source heat pumps, the work is more extensive. A trench system (horizontal ground loops) requires a fair amount of garden space, or a vertical borehole uses less space but is a higher cost due to the specialist drilling.

5. Electrical and Plumbing Connections

Your new system is integrated into your home’s heating and electrical systems. This might involve wiring upgrades, connection to your existing or new thermostats, and careful commissioning to ensure everything runs as it should.

6. Aftercare & Handover

You’ll receive guidance on how to operate your new system, set your controls, and maximise efficiency. You should always feel comfortable to contact your installer with any questions you have post-installation. Many installers also offer servicing packages to keep your system in top condition.

What’s involved in installation?

Installing a heat pump is a big step forward for your home, and will involve some element of disruption. However, with a good installer and a clear process, most systems can be fitted with minimal hassle and long-term gain.

1. Home Survey & Heat Loss Assessment

It all starts with a detailed, no-obligation survey by an MCS-certified installer. They’ll assess your property’s size, layout, insulation, and current heating system to calculate how much heat your home needs, known as a heat loss assessment. This helps determine the right size and type of heat pump and ensures your system is designed for comfort and efficiency.

2. System Design & Specification

Once the survey is complete, your installer will create a bespoke system design. This includes:

• Recommendation of an air source or ground source heat pump.

• Sizing your hot water cylinder and radiators (or underfloor heating).

• Planning where units, pipework, and controls will go.

• Ensuring all elements comply with building regulations and grant requirements

3. Installation

Installation typically takes approximately 5 days, depending on the complexity of the system and your home. For air source heat pumps, the outdoor unit is usually fitted near an external wall and mounted on a small concrete base. Inside the home, work may involve installing or upgrading a hot water cylinder, fitting larger radiators if required, and connecting electrical controls.

If you're opting for a ground source heat pump, the process can take longer due to the need for trenching or vertical borehole drilling. Regardless of the system type, experienced installers will aim to minimise disruption and keep heating downtime to a minimum — often no more than a single day — while working cleanly and efficiently throughout.

4. Commissioning, Handover & Aftercare

Once everything is in place, your installer will:

• Test and commission the system

• Show you how to use your controls and optimise your settings

• Provide user manuals and warranty information

Some MCS installers also offer ongoing servicing and aftercare packages, so you can keep your heat pump running smoothly for years to come.

Will it be disruptive?

Most homeowners are pleasantly surprised at how straightforward the installation process is. That said, there are a few simple steps you can take to help minimise any disruption. If possible, try to book your installation during the warmer months, when you’re less reliant on your heating system. It’s also helpful to clear space in advance where the indoor and outdoor units will be installed, allowing the work to proceed more smoothly.

A good installer will talk you through what to expect at each stage and help plan the work around your schedule to keep inconvenience to a minimum.

Typical Timeline

• Initial consultation & survey 1–2 weeks to arrange
• System design & quote 1–2 weeks
• Installation 2–5 days (air source)
• Groundworks (if required) Additional 1–2 weeks
• Handover & aftercare setup 1 day

From first contact to finished installation, most projects are completed within 4 to 8 weeks, depending on availability and system type.

Remember, You Don’t Need to Do It All at Once

At Warmur, we understand that every home is different, and every homeowner is on their own journey. That’s why we don’t just drop in a heat pump and disappear.

We take a phased approach that fits your home, your budget, and your lifestyle. We can start by installing a heat pump that works with your existing radiators and run it at slightly higher temperatures, helping you start saving money and cutting carbon immediately.

Then, when the time is right, we can help you:

Upgrade your heating system for even greater efficiency

• Add solar panels to generate your own electricity
• Install a battery to store energy and become less reliant on the grid
• Access the best tariffs for low-cost, off-peak energy
• Optimise your system with smart controls and ongoing performance monitoring.

With Warmur, you’ll always know your next best move, a clear plan that makes every upgrade smarter, not harder.

What you need to ask when choosing an installer

Installing a heat pump is a smart investment, but like any major home upgrade, the outcome depends heavily on who you trust to do the work. The right installer doesn’t just fit the system; they guide you through every step, from initial design to aftercare, and help you make confident, informed decisions along the way.

With demand for heat pumps growing rapidly in Scotland, it's more important than ever to work with a qualified, experienced professional who understands your home and heating needs. Choosing the right installer makes all the difference — with expert guidance, you’ll get the best performance, maximise your savings, and ensure you don’t miss out on available funding.

By asking the right questions early on, you can protect your investment, avoid common pitfalls, and ensure you’re working with someone who has your best interests and your comfort at heart. This section will help you know exactly what to ask, what good service looks like, and which accreditations to look out for before you say yes.

Top 8 Questions to Ask Your Installer

1. Are you MCS-certified?

Only MCS-certified installers can unlock access to government grants and meet quality standards.

2. What type of heat pump do you recommend for my home, and why?

A good installer will tailor their advice to your property, energy use and goals.

3. Will I need to upgrade my radiators or hot water system?

Understanding this early helps you budget and plan realistically.

4. Can you provide a full heat loss calculation?

This is essential for sizing the system correctly, not just for performance, but for funding eligibility.

5. Do I have options in terms of how it is designed, for example, whether it's for low temperature or low installation disruption?

Your installer should be willing and able to tailor your heating system to suit your priorities, whether that’s maximum efficiency at low temperatures or a design focused on minimal installation disruption.

6. What’s included in your quote?

Ask whether the price covers the heat pump, hot water cylinder, electrical work, radiator upgrades, commissioning, and aftercare.

7. How disruptive will the installation be?

A clear explanation of the process and timeline helps you prepare and reduces stress.

8. What aftercare and servicing do you provide?

Ongoing support matters. Make sure you know what help is available once the system is up and running.

What Good Service Looks Like

A reputable installer will:

• Offer clear, written quotes with no hidden costs.

• Take the time to explain your options.

• Provide a detailed system design and heat loss report.

• We can help you with your Home Energy Scotland grant application.

• Ensure you understand how to operate your system.

• Offer ongoing support and maintenance packages.

If an installer seems vague, pushes a one-size-fits-all solution, or can't provide credentials, it's best to look elsewhere.

Accreditations to Look Out For

To ensure quality, safety, and eligibility for funding, check that your installer holds the following:

• MCS (Microgeneration Certification Scheme): The gold standard for low-carbon heating. Required for government funding.

• RECC (Renewable Energy Consumer Code): Ensures fair sales practices, consumer protection, and good customer service.

The right installer won’t just fit your system, they’ll guide you through the entire journey with care, clarity and professionalism. So don’t be afraid to ask questions, take your time, and choose a partner who makes you feel informed and confident every step of the way.