Are heat pumps expensive to run? When designed and installed correctly by experts, heat pumps are highly cost-effective and use significantly less electricity than traditional heating systems. A heat pump typically produces 3 to 4 units of heat for every 1 unit of electricity it consumes. This 300%+ efficiency makes them a greener and potentially cheaper alternative to fossil fuels.

What funding or grants are available for a heat pump? Homeowners in England and Wales can currently claim a £7,500 Boiler Upgrade Scheme (BUS) grant towards the installation of an Air Source or Ground Source Heat Pump. Furthermore, there is currently 0% VAT on the installation of renewable technologies. As certified MCS installers, Total NRG will handle the entire BUS grant application on your behalf and apply the discount directly to your quote!

Boiler Upgrade Scheme uplift:

• A temporary £1,500 increase to the BUS grant for homes heated by oil and LPG in England and Wales, taking the total grant to £9,000.
• Further details to be confirmed officially, but Matthew Aylott, Senior Policy Advisor at DESNZ, posted on LinkedIn (LINK).
  • DESNZ are working with Ofgem to deliver the grant uplift as soon as possible, and a grant change notice will be published on GOV.UK. In the coming weeks, we will provide further details.
  • They are expecting the uplifted grant to be available in July 2026.

Myth 1: Heat pumps are only suitable for new builds. The Truth: Heat pumps can successfully heat even the oldest of properties! We estimate that well over 50% of existing heating systems can be converted to heat pumps without major modifications. With an appropriate system design from Total NRG, modern heat pumps can be utilised in older renovations, even alongside traditional radiators (though some may need to be upgraded to larger sizes).

Myth 2: Heat pumps don't work when it's freezing outside. The Truth: Modern heat pumps are explicitly designed to extract heat from cold air. The premium Stiebel Eltron heat pumps we install feature large surface areas and Enhanced Vapour Injection (EVI) technology, enabling them to operate highly efficiently down to -25°C!

Myth 3: Will need a backup boiler. The Truth: No, you won't! If your system is designed and sized correctly by Total NRG, your heat pump will provide 100% of your heating and hot water demands. Depending on the model, our Stiebel Eltron heat pumps can deliver a flow temperature of up to 75°C without the need for an immersion heater or a backup fossil-fuel boiler.

Myth 4: Are heat pumps expensive to run? When designed and installed correctly by experts, heat pumps are highly cost-effective and use significantly less electricity than traditional heating systems. A heat pump typically produces 3 to 4 units of heat for every 1 unit of electricity it consumes. This 300%+ efficiency makes them a greener and potentially cheaper alternative to fossil fuels.

Are heat pumps noisy? Heat pumps are generally not considered to be noisy, but the exact decibel level depends on the type of system and where it is installed:

• Ground Source (GSHP): These are the quietest type. A Stiebel Eltron WPE-I generates around 38 decibels (equivalent to a quiet refrigerator hum).

• Air Source (ASHP): These are slightly louder due to the outdoor fan. Standard units run around 48 decibels (comparable to moderate rainfall). However, in "Quiet Mode," our Stiebel Eltron ASHPs can drop to as low as 35 decibels—quieter than a whisper!

How much outdoor space is needed for a heat pump?

• Air Source (ASHP): The outdoor unit requires about 2 meters of vertical space and 2 meters of width, plus 2 meters of unobstructed space in front of the fans for proper airflow.

• Ground Source (GSHP) Trenches: You need a substantial amount of clear land (no trees or woodland). For example, a 10kW heating load might require four 100-meter-long trenches.

• Ground Source Boreholes: If space is limited, we can drill vertically. Boreholes only require enough space for the drilling rig to access the site and are usually spaced 9 meters apart.

How much indoor space is needed for the Plant Room? Because heat pump systems require a hot water cylinder, a buffer tank, and circulation pumps, they generally need more space than a standard combi-boiler.

• A typical ASHP Plant Room requires about 1.8m x 1.5m of space.

• A typical GSHP Plant Room requires about 2.5m x 1.5m (since the actual heat pump unit is housed indoors).

• Note: Your plant room does not need to be inside the main house! It can be located in a detached garage or barn up to 100 meters away, with highly insulated underground district-heating pipes.

What size heat pump do I require? You should never guess the size of a heat pump. Total NRG conducts a rigorous room-by-room heat loss calculation for every project. This ensures we specify the exact size of the heat pump and hot water cylinder required for your specific property, preventing you from paying for an oversized unit or struggling with an undersized one.

What is a buffer tank, and why do I need one? A buffer tank is a water-filled cylinder that acts as a hydraulic separator between the heat pump and your home's heating circuits. It is absolutely essential for two reasons:

1. Defrosting: In winter, an Air Source heat pump's outdoor coil can freeze. The pump must briefly reverse its cycle to melt the ice. The buffer tank provides a dedicated supply of warm water for the pump during this defrost cycle, preventing it from stealing heat from your radiators!

2. Efficiency: Heat pumps work best when they run for long, continuous periods. A buffer tank stores excess heat, so the pump doesn't have to turn on and off constantly whenever a single-room thermostat calls for heat.

Can I cool my building with a heat pump? Yes! Total NRG offers summer cooling solutions: See PDF Guide

Total NRG offers reversible heat pumps that can provide active cooling during the summer months. The heat pump essentially runs in reverse, chilling the water in your system. This is incredibly effective when paired with Underfloor Heating or a Mechanical Ventilation Heat Recovery (MVHR) system.

• Passive Cooling (GSHP only): The naturally low ground temperature is transferred to your underfloor heating system without turning on the heat pump compressor.

• Active Cooling (ASHP & GSHP): The heat pump compressor runs in reverse to actively generate chilled water, which can be distributed via your underfloor heating or a Mechanical Ventilation (MVHR) system.

Can I power my heat pump with Solar Panels? Yes! This is the ultimate way to lower your running costs. Total NRG can seamlessly integrate a Solar PV system with your heat pump. Instead of exporting your excess solar energy back to the grid for pennies, your heat pump will use that free electricity to heat your home and provide hot water.

What exactly does an MVHR system do?

An MVHR system is a whole-house ventilation unit that continuously extracts stale, moist, and polluted air from "wet" rooms (like kitchens and bathrooms). Before venting that stale air outside, it passes it through a heat exchanger to capture up to 96% of the heat. This recovered heat is then transferred to fresh, filtered air brought in from the outside, which is gently distributed into your living areas and bedrooms.

Do I legally need an MVHR system for a new build?

While you aren't legally forced to use MVHR specifically, modern homes are built to be incredibly airtight to prevent heat loss. Because of this airtightness, Building Regulations Part F legally requires adequate ventilation to prevent mould and remove indoor pollutants. A professionally designed MVHR system is widely considered the absolute best and most efficient way to meet these strict Part F requirements without wasting your home's heat.

Can an MVHR system cool my home in the summer?

Yes! All of our premium Stiebel Eltron MVHR systems feature a "Summer Bypass" mode. On warm days, if the outside air is cooler than the inside air (like in the evening), the system automatically bypasses the heat exchanger to draw that cool, fresh air directly into the house. Even better: If your MVHR is paired with a reversible Stiebel Eltron Heat Pump from Total NRG, we can provide Active Summer Cooling—circulating chilled air throughout the house to easily satisfy Building Regulations Part O (Overheating).

Are MVHR systems noisy?

Not when designed and installed by experts! A poorly installed system with undersized ducting can whistle or hum, but a premium Stiebel Eltron system installed by Total NRG is virtually silent. We calculate the exact airflow requirements for every room and use acoustic silencers and correctly sized ducting to ensure the system operates quietly in the background.

Can MVHR be retrofitted into an older, existing property?

Yes, but it requires careful consideration. MVHR is most effective in homes that have been heavily insulated and draught-proofed. If an older home is very "leaky," an MVHR system won't be nearly as effective because your heat is already escaping through gaps in the walls, floors, and windows. We often install MVHR during deep, "back-to-brick" retrofits or major extensions.

How much does an MVHR system cost to run, and what maintenance does it need?

Because the fans use highly efficient, low-energy motors, the electricity cost to run the unit is incredibly low (often just pennies a day). More importantly, the financial value of the heat it saves far outweighs the cost of running the fans! In terms of maintenance, it is very straightforward. Homeowners simply need to slide out and replace the air filters every 6 to 12 months (depending on outdoor air quality) to keep the air fresh and the system running efficiently.

Can I use radiators with a heat pump?

Yes, absolutely! While underfloor heating is fantastic, heat pumps work exceptionally well with standard wall-mounted radiators. In fact, thousands of retrofitted homes in the UK run their heat pumps entirely on radiators. The key is ensuring that the radiators are correctly sized for the specific room they are heating.

Do I have to replace all my existing radiators to get a heat pump?

Not necessarily. Because a heat pump operates at a lower, more continuous flow temperature than a gas boiler (which blasts very hot water in short bursts), the radiator's surface area needs to be large enough to emit enough heat into the room. Total NRG will conduct a full, room-by-room heat-loss calculation. Often, we find that many of your existing radiators are already big enough. For rooms that need more heat, we simply upgrade the specific radiator to a slightly larger size or a double- or triple-panel radiator (Type 22 or Type 33).

Can I mix underfloor heating and radiators in the same house?

Yes, this is one of the most common and efficient setups we install! It is very popular to have underfloor heating downstairs in the main open-plan living areas (for luxurious, ambient heat) and correctly sized radiators upstairs in the bedrooms (for quick, responsive heat). We install a dual-zone control system so the heat pump seamlessly manages both temperatures perfectly.

Do heat pump radiators take longer to heat a room?

Because heat pumps use a "low and slow" approach, they don't provide the sudden blast of intense heat that a fossil-fuel boiler does. Instead, your radiators will feel warm to the touch (rather than burning hot) and will run consistently to maintain a perfectly stable, comfortable temperature in the room all day long. This is actually much more energy-efficient and comfortable than a house that constantly fluctuates between freezing cold and boiling hot!

Can I power my heat pump with Solar Panels?   

Yes! This is the ultimate way to lower your running costs. Total NRG can seamlessly integrate a Solar PV system with your heat pump. Instead of exporting your excess solar energy back to the grid for pennies, your heat pump will use that free electricity to heat your home and provide hot water.

Can I add battery storage to my Solar PV system?

Yes, and it is highly recommended! Without a battery, any excess solar energy you generate during the day but don't use immediately is sent back to the national grid. By adding a solar battery, you can store that free, clean electricity and use it in the evening when the sun goes down and energy tariffs are often at their highest. This massively increases your energy independence, slashes your electricity bills, and lets you power your home (or your heat pump) around the clock with your own self-generated power.

What is the difference between an AC and DC battery, and why do you only use DC?

When storing solar energy, the way the battery connects to your system matters. Solar panels naturally generate electricity as DC (Direct Current), but your home uses AC (Alternating Current).

• AC-Coupled Batteries: Solar energy is converted from DC to AC for use in the house. Any excess energy must be converted back to DC to be stored in the battery, then converted back to AC when you want to use it. Every single conversion loses energy (known as round-trip efficiency loss).

• DC-Coupled Batteries (The Total NRG Choice): Solar energy flows directly from the panels into the battery as DC power, with no conversions. It is only converted to AC once, exactly when your house needs it.

At Total NRG, we exclusively design and install DC-coupled battery systems for new Solar PV installations because they offer vastly superior performance. Here are the main benefits:

• Maximum Efficiency: By eliminating the multiple AC/DC conversions, you retain significantly more of the free solar energy you generate.

• A Sleeker, Neater Installation: AC systems require multiple inverters (one for the panels, one for the battery) bolted to your wall. Our DC systems utilise a single, smart "Hybrid Inverter" that manages both the solar panels and the battery in one neat unit.

• Higher Reliability: Fewer components and inverters mean fewer points of failure, making the system much more reliable over its 10-to-15-year lifespan.

• More Cost-Effective: Because we only need to install one hybrid inverter rather than two separate units, it is a much more cost-effective way to future-proof your home from day one.

Can my solar inverter and battery be installed outside, or do they have to be inside?

While many modern hybrid inverters and solar batteries are fully weatherproof (often IP65-rated) and can technically be installed outside, Total NRG highly recommends installing them indoors whenever possible—such as in an attached garage, utility room, or dedicated plant room.

Here is why indoor installation is always our preference:

• Temperature Sensitivity: Solar battery chemistry is highly sensitive to extreme cold. During freezing UK winters, an outdoor battery's efficiency drops significantly, and its internal management system may temporarily stop charging to protect the cells. Keeping it indoors ensures it operates at peak efficiency year-round.

• Maximum Lifespan: Keeping your equipment in a stable, indoor climate prevents unnecessary wear and tear from frost, driving rain, and direct summer sunlight, ultimately maximising the lifespan of your investment.

• When outside is the only option: If indoor space is completely restricted, we can safely install your system outdoors. However, we will carefully design the layout to ensure the equipment is placed in a shaded, sheltered area (often against a north-facing or east-facing wall) to protect it from direct sunlight and the worst of the winter weather.

Does underfloor heating work well with a heat pump?

Yes, they are the absolute perfect match! Heat pumps operate most efficiently when producing lower water flow temperatures (typically between 35°C and 45°C). Because underfloor heating covers a much larger surface area than a small radiator, it requires lower temperatures to heat a room comfortably. Pairing a heat pump with UFH guarantees maximum efficiency and lower running costs.

Can underfloor heating be installed in an existing property?

Yes. Underfloor heating can often be installed in existing homes as well as new builds. Total NRG specialises in retrofit underfloor heating systems, including low-profile and routed solutions that work with existing floor structures while minimising disruption.

Is underfloor heating only suitable for new builds?

No. Although underfloor heating is commonly fitted in new build properties, it can also be an excellent option for renovations and older homes. With the right system design, Total NRG can install underfloor heating in many existing properties without requiring major structural changes.

Will underfloor heating raise the floor height?

Not always. Modern retrofit underfloor heating systems are specifically designed to keep any increase in floor height to a minimum. In some cases, Total NRG can install low-profile systems over the existing floor or route the pipework into the floor itself, helping to avoid noticeable floor build-up.

Can underfloor heating be installed without digging out the floors?

In many cases, yes. Depending on the floor construction, underfloor heating can sometimes be installed over existing floorboards or routed into concrete floors without removing them.

How do I know which underfloor heating system is right for my home?

The best system depends on your property, floor construction, available floor depth, and heating requirements. Total NRG will assess your home and recommend the most suitable underfloor heating system to deliver comfort, efficiency, and long-term performance.

What type of flooring works best with underfloor heating?

Hard, dense materials are the best thermal conductors. Stone, ceramic tiles, and polished concrete will heat up quickly and hold the heat brilliantly. However, engineered wood, Luxury Vinyl Tiles (like Amtico or Karndean), and high-quality laminates also work exceptionally well. You can even use carpet, provided the combined "tog" rating of the carpet and underlay is low enough to allow heat to pass through (usually 2.5 tog or less).

Is underfloor heating cheaper to run than radiators?

Generally, yes. Because underfloor heating operates at a much lower temperature than traditional radiators, your heat pump doesn't have to work as hard to heat the water. This means your system runs much more efficiently, often resulting in running costs that are 15% to 25% lower than a standard radiator setup. Plus, it provides a much more luxurious, even distribution of heat across the entire room with zero cold spots!

A professional, room-by-room heat-loss calculation is the foundation of any successful heat pump installation. Instead of simply guessing or using outdated "rules of thumb," Total NRG conducts a precise mathematical assessment of your property. This ensures we select the exact heat pump size and design an efficient heating system tailored specifically to your home.

1. Perfect Sizing for Optimal Efficiency

Oversizing or undersizing a heating system leads to massive energy inefficiencies. If a heat pump is too small, your home will be cold; if it is too big, it will "short-cycle" (turn on and off constantly), burning unnecessary electricity and wearing out the compressor. Our room-by-room calculation accurately sizes the heat pump, ensuring it operates at peak efficiency, reducing your energy consumption and lowering your bills.

2. Zonal Control & Custom Comfort

Every room in your home has unique characteristics—from its size and insulation levels to its exposure to external elements (like wind and shade). By calculating the exact thermal demand for each space, Total NRG can enable precise zonal control. Whether via Underfloor Heating or correctly sized radiators, we ensure the right amount of heat is delivered to every single room based on your individual comfort preferences.

3. Accounting for Windows, Doors & Insulation

Windows and doors are the primary routes for heat to escape. Each room has a unique arrangement of glazing, which drastically affects its thermal performance. A true room-by-room calculation measures these openings precisely, allowing us to factor them into the heat pump's required output, or advise you on where simple insulation upgrades might save you money.

4. Accurate Sizing of the Hot Water Cylinder

The heat pump isn't the only component we calculate. By determining your property's overall heating and hot water demands based on your home's size and your family's usage, Total NRG can perfectly size your domestic hot water cylinder. This ensures all components are properly matched, so you always have plenty of hot water without wasting energy heating a tank larger than you need.

5. Optimising Ground Array Sizing for GSHPs

If you are opting for a Ground Source Heat Pump (GSHP), the ground array is a critical component of the system. A room-by-room analysis helps us determine the overall heating demand and guides the exact sizing of the ground loop or boreholes. This precision is essential to ensure the array can efficiently extract enough heat from the earth to provide long-term, reliable performance for decades to come.

6. Mandatory for the £7,500 BUS Grant & MCS Compliance

Proper heat loss calculations are not just a recommendation; they are an industry requirement. To comply with the Microgeneration Certification Scheme (MCS)—and to successfully claim your £7,500 Boiler Upgrade Scheme (BUS) grant—a detailed analysis of your heating requirements is mandatory. Total NRG provides all the necessary documentation to demonstrate that your heating system design meets strict regulatory standards, enabling us to claim the grant seamlessly on your behalf.

Summary

A room-by-room heat loss calculation is a comprehensive, tailored approach to future-proofing your home. By considering the specific architectural characteristics of your property, Total NRG guarantees an energy-efficient, highly effective heating system that works perfectly from day one.