Underfloor heating with heat pumps

Underfloor heating and heat pumps are the ideal combination if you want a system that delivers comfort and high energy efficiency throughout the year. Because both operate at low water temperatures, they work more efficiently together than traditional radiators, help reduce your household emissions and can have lower running costs. 

The future of home heating and cooling

Home heating is undergoing a transformation across the UK, driven by stricter energy standards, rising fuel costs and growing environmental awareness.

Underfloor heating combined with heat pump technology is leading the way, offering a low-carbon, highly efficient and incredibly comfortable alternative to traditional fossil fuel systems, for both heating and, in some cases, cooling.

Homeowners are drawn to the even distribution of heat, the reduced operating costs and the design freedom that comes from not having to work around obtrusive radiators.

So, what is it about these two technologies that makes them so compatible? Why is an air source heat pump best for underfloor heating?

We’ll uncover the answers to these questions and more in this article, while delving deep into the science, practicality and sustainability of heat pumps for underfloor heating and hot water.

What is underfloor heating?

If you’ve ever walked on a toasty warm floor, even when it’s tiled, you’ll know just how comforting and luxurious underfloor heating feels.

With underfloor heating, the home is heated by a network of pipes laid beneath the floor, rather than radiators on the walls.

As well as that cosy feeling underfoot, heat is distributed much more evenly, so you don’t get the hot and cold spots or uncomfortable draughts that are common with radiators. There is less dust circulation and the indoor air quality is generally better as a result.

This is because underfloor heating uses radiant heat transfer, which gently warms surfaces and objects, whereas radiators rely on the circulation of warm air.

Water-based, or hydronic, underfloor heating systems also circulate warm water at much lower temperatures than radiators - around 25–35°C compared to 45–75°C.

This lower operating temperature can cut energy consumption by 10-15% compared to traditional heating systems.

It’s also one of the main reasons why a heat pump provides the perfect heat source for underfloor heating. Daikin heat pumps are ideally suited for pairing with hydronic underfloor systems.

Why are heat pumps and underfloor heating the perfect match?

A heat pump is an innovative low carbon heating and cooling system that is growing in popularity as we move away from fossil fuels and towards renewable, low-carbon alternatives.

Instead of having to burn fossil fuels to create heat, a heat pump extracts existing thermal energy from the air, ground or water, and moves it from outside to inside.

It works in much the same way as a refrigerator, except in reverse. If you’d like a deeper understanding of the technology behind this, you can read our guide on how heat pumps work.

Because of their ease of installation, air source heat pumps are the most common type of heat pump for residential homes, drawing their energy from the air outside, even at temperatures as low as -28°C.

The efficiency advantage of a heat pump

Other advantages of a heat pump include ability to provide year-round heating and cooling at incredibly high efficiencies and they can lead to lower running costs.

• A heat pump can deliver 3-5 kWh of heat for every 1 kWh of electricity consumed, making it 300% to 500% more efficient than traditional gas boilers under optimal conditions.
• Heat pumps are most efficient when producing water at lower temperatures, and underfloor heating is specifically designed to work at these lower levels.
• By circulating warm water across a large surface area, underfloor systems can comfortably heat a room with water temperatures of around 30°C. This allows a heat pump to run at its optimal efficiency level.

You can read more about heat pump efficiency in our dedicated guide to how heat pumps work.

A stable environment, consistent comfort

Combining heat pumps with underfloor heating maintains a more consistent temperature, reducing the stop-start cycling seen with gas boilers.

This, in turn, maintains a more stable indoor environment and extends the lifespan of the equipment, because it's not having to work so hard.

As a homeowner, you benefit from reduced energy bills, a quieter heating system, and consistent comfort, instead of hot and cold fluctuations.

It’s why we’re seeing more Daikin heat pumps being paired with underfloor heating.

What is ‘low leaving temperature’ and why does it matter?

In simple terms, underfloor heating enables your heat pump to work at lower, more efficient water temperatures.

To get a bit more technical, this synergy is down to the leaving water temperature (LWT) – that is the temperature of the water as it leaves the heat pump before being distributed to the heating system.

With underfloor heating, a typical LWT of 25-35°C is enough to maintain a comfortable indoor temperature. With radiators, however, the LWT needs to be 45-75°C to reach the same level of warmth, so the heat pump has to work harder.

Optimising LWT with a Daikin Altherma heat pump, for example, can cut energy consumption by 10% - 15%  compared to conventional high temperature systems.

Can you cool your home with underfloor heating?

While it’s called underfloor ‘heating’, did you know you can also cool your home with an underfloor system?

Modern reversible heat pumps can function as gentle cooling systems in the summer by circulating cool water through the same pipe network instead. The system absorbs excess indoor heat and transfers it outside.

This radiant method of cooling is comfortable and consistent, keeping you cool without draughts or condensation build up.

As summers continue to get warmer in the UK, underfloor heating and cooling can help you feel comfortable all year round, with just one combined heating system.

What are the main components of an underfloor heating system?

A complete underfloor heating system is made up of:

• A heat pump: The heat pump is at the heart of the system. It extracts thermal energy from the air, ground, or water to provide a more efficient form of heating.
• Pipework and manifolds: Warm or cool water is distributed through pipes embedded in the floor. These are connected to a manifold that regulates the flow.
• Thermostats and smart controls: Thermostats and smart controls ensure each zone (individual rooms or areas) of your system is working at optimal comfort levels, without wasting energy.
• Insulation and screed: An effective system relies on high-quality insulation beneath the pipework to prevent heat being lost into the ground below. A layer of screed on top of the pipes acts as a thermal store.

When designed and installed correctly, these components work in complete harmony to create a highly responsive, efficient and long-lasting climate control system.

What are the types of heat pumps for underfloor heating?

• Air source heat pumps – These extract heat from the air outdoors, even in sub-zero temperatures, and turn it into efficient indoor heating or cooling for the home. They dominate the residential market due to their flexibility and relative low installation cost. They can easily be paired with underfloor heating.
• Ground source heat pumps – Draw thermal energy from the earth via loops buried in the ground. They achieve higher efficiencies but do need garden or borehole space and are more expensive to install.
• Water source heat pumps – These are less common but can work well in homes near lakes or rivers, offering high efficiency and a stable output.

Deciding which heat pump is best for your underfloor heating depends on a number of factors.

What is the difference between water-based underfloor heating and electric underfloor heating?

While Daikin heat pumps work best with water-based underfloor heating systems, you can also get electric underfloor heating, so it’s worth being aware of both types.

As we mentioned above, water-based systems operate very efficiently with a heat pump due to the lower water temperatures required.

Electric-based systems, however, operate independently from external heat sources and are typically more expensive to run than a water-based system.

This means your running costs could be significantly higher over the course of a heating season.

Top benefits of underfloor heating

There are many reasons why people are choosing underfloor heating as the perfect partner to their heat pump, with several lifestyle and financial benefits on offer.

These include:

• Minimal maintenance, requiring just occasional inspections of the underfloor heating manifold and annual checks on the heat pump
• Quiet operation – the system is almost silent with no humming fans or ticking radiators
• Integrates seamlessly with smart home systems for remote control and scheduling to optimise energy use
• Compatible with renewable energy such as rooftop solar to further boost efficiency and reduce reliance on fossil fuels
• Future-proofing your home against volatile energy prices providing predictable, lower running costs

Underfloor heating installation in a nutshell

Put very simply, installing underfloor heating can be described in the following five basic steps:

• Step 1: Preparing the sub-floor to add high-performance insulation
• Step 2: Laying out the pipe network in carefully calculated loops on top of the insultation to ensure even heat distribution
• Step 3: The pipes are fixed securely to the floor before the screed layer is poured over the top
• Step 4: Once the screed has cured, the heat pump is connected and the system is filled with water and pressure-tested
• Step 5: Expert installers calibrate the flow rates and thermostats to achieve the right comfort levels in each zone/area.

The whole process can take three to seven days for a typical home depending on the size and complexity.

Is underfloor heating better suited for new builds or retrofit properties?

Because underfloor heating involves adding insulation, pipes and screed, it can raise the height of the floor.

In a new build, this can easily be factored in at the design stage. While it can naturally prove more challenging in an existing property, there are low-profile underfloor heating panel systems available on the market that add as little as 15-20mm to the floor height.

Ask your Daikin installer about low-profile retrofit systems if you're considering modernising an existing property.

The energy efficiency of a Daikin heat pump

As we’ve discussed, the lower water temperatures needed for underfloor heating significantly boost the efficiency of a heat pump – often resulting in 20-30% lower running costs compared to high temperature systems.

Daikin heat pumps are incredibly efficient in themselves. The Seasonal Coefficient of Performance (SCOP) values of Daikin heat pumps typically exceed 4.5 – which means for every one unit of electricity used, more than four times that amount of heat is generated.

The process is reversed for energy efficient cooling in summer.

How can smart controls help to lower your energy bills?

Installing a heat pump and underfloor heating is the first step; if you really want to maximise efficiency and get the most out of your investment, effective control is key.

This means intuitively adapting the system to the needs of your family, and automatically adjusting for weather conditions and electricity tariffs.

You can do all of this easily via Daikin’s Onecta app, which integrates perfectly with modern underfloor heating systems.

Using Onecta, you can:

• Get precise temperature regulation for each room or zone
• Only heat the rooms you use, when you use them
• Monitor your energy consumption in real time
• Benefit from algorithms that learn your household routines
• Optimise performance for weather changes and occupancy patterns

Why is home insulation so important for underfloor heating?

Insulation is another vital piece of the puzzle if you’re looking to significantly improve the energy efficiency of your home as a whole.

Making sure your home is properly insulated throughout will help maximise the performance of your heat pump and underfloor heating.

This includes maintaining high insulation levels for walls, windows and roofs, and checking for air tightness to prevent warm or cold air escaping.

Adding insulation, upgrading windows and doors and sealing gaps will not only make the home more comfortable, but will also reduce energy wastage and boost savings on energy bills.

What is the cost of a heat pump and underfloor heating?

If you’re thinking about getting a heat pump and underfloor heating for your home, one of your main considerations will likely be cost.

The cost of a heat pump and underfloor heating mainly comes down to two factors – cost of installation and cost to run the system over the long-term.

• Installation costs: Installing a combined heat pump and underfloor heating system typically costs €12,000–€18,000 for an average three-bedroom home, depending on individual circumstances such as type of heat pump, the size of the floor and the condition of the property.
• Heat pump subsidies: Many countries now offer subsidies for heat pumps which can help offset the initial cost, so it’s definitely worth checking what heat pump grants are available where you live.
• Running costs: These are significantly lower than electric radiators, and competitive when compared with gas boilers, particularly as gas prices fluctuate. Running costs can be reduced further by taking advantage of special electricity tariffs, or adding solar panels – which we will come on to in the next section.
• Maintenance requirements: Underfloor heating has few moving parts and doesn’t need much looking after beyond occasional manifold inspections. Heat pumps benefit from an annual service to check refrigerant levels, filters and system performance. Your local Daikin installer can take care of servicing for you.
• Longevity: With proper care, underfloor heating pipes can last over 50 years, while modern heat pumps typically last 15 to 20 years before requiring major replacement. It’s therefore worth assessing value for money over the long term against your initial renewable heating system investment.

Source: Checkatrade

Environmental benefits of a heat pump with underfloor heating

You can cut your household emissions by up to 70% compared to fossil fuels when you switch to a heat pump with underfloor heating, depending on the electricity mix.

This supports EU net zero targets and helps buildings achieve higher energy efficiency ratings.

How does underfloor heating work with solar panels and battery storage?

Heat pumps with underfloor heating integrate seamlessly with solar panels. Adding battery storage into the mix as well would enable you to become mostly energy independent – with your heating and cooling being run largely from self-generated energy.

The solar panels power the heat pump directly during the day, while excess energy can be stored in the battery to be used in the evening, or at times when electricity tariff are highest. This reduces reliance on the grid, minimises the impact of fluctuating energy costs, and can take your energy bills to almost zero in the summer.

Can a heat pump with underfloor heating increase my home's value?

Installing environmentally friendly heating and energy solutions in your property makes it more attractive to buyers and can increase its value. According to Rightmove, a property moving from an EPC rating of F to a C could increase its value by an average of 15%, or almost £56,267 when looking at the national average asking price. 

Source: Rightmove Greener Homes Report 2023. 

Heat pump with underfloor heating FAQs

We’ve covered a lot of ground in this article so far, but here’s a round-up of answers to some of the most common questions we get asked about heat pumps with underfloor heating.

• Is a heat pump with underfloor heating enough to heat my entire home?
  Yes, in most well-insulated properties this is enough to provide comfortable heating and cooling all year round.
• How long does it take to install underfloor heating with a heat pump?
  In an average home, installation takes between three and seven days.
• Can I cool my home in summer with underfloor heating?
  Yes, modern heat pumps are reversible and can cool as well as heat.
• What if my home isn’t well insulated?
  Insulation upgrades are recommended to get the best possible performance from your heat pump and underfloor heating system.

How do I choose the right heating system for my home?

While there are a lot of factors to consider, ultimately the right system for you will depend upon your home, lifestyle and location.

You don’t need to navigate it all alone, though. Our network of Daikin installers offers tailored advice to ensure you get a system that is designed especially for you, delivering maximum comfort and maximum efficiency. 

To find a local Daikin installer visit our Find an Installer page on our website.

Final thoughts: Comfort, efficiency and sustainability in one system

Underfloor heating allows a heat pump to maintain comfortable indoor temperatures using much lower water temperatures than traditional radiators. Operating at these lower temperatures helps the heat pump work more efficiently. The result is a future-proof system that heats and cools your home with minimal energy waste. It's one of the most effective ways to combine comfort, sustainability and long-term savings.

Key takeaways

• Underfloor heating allows a heat pump to run at optimal efficiency, because of low water temperatures (25-35°C).
• The system provides stable, draught-free comfort and can help with both heating and cooling.
• Pairing a heat pump with underfloor heating can reduce running costs by 20-30%.
• The combination reduces greenhouse gas impact when powered by clean electricity and supports EU net zero goals.
• Installing a heat pump can increase the value of your home and make it more attractive to buyers when you come to sell it.