Air Source Heat Pump Installation & Cost

Air Source Heat Pump Installation

Properly Designed Low-Carbon Heating for Your Home

An air source heat pump installation can provide efficient heating by collecting naturally occurring heat from the outside air and transferring it into your home.

Unlike a gas, oil or LPG boiler, a heat pump does not create heat by burning fuel. It uses electricity to move heat from one place to another, allowing a correctly designed system to deliver more heat energy than the electrical energy it consumes.

However, installing a heat pump is not simply a matter of removing the boiler and connecting another appliance to the same pipes.

A successful ASHP installation should be designed around:

The heat loss from the property.

The size and condition of the radiators.
The heating flow temperature.
The existing heating pipework.
Hot-water requirements.
The size and position of the hot-water cylinder.
The electrical supply.
The outdoor-unit position.
Noise and neighbouring properties.
Condensate drainage.
Heating controls.
The way the household uses its heating.
Planned extensions and home improvements.

A correctly designed air source heat pump can provide comfortable, dependable heating throughout the year. A poorly designed system may leave rooms difficult to heat, increase electricity consumption and disappoint the homeowner.

The APN Boilers network helps homeowners find experienced heat-pump professionals who can assess the complete property rather than simply quote for an outdoor unit.

What Is an Air Source Heat Pump?

An air source heat pump takes heat from the outside air and upgrades it to a temperature that can be used within the property.

It can continue extracting heat even when the outside temperature is below freezing.

The two principal types used in homes are:

Air-to-Water Heat Pumps

An air-to-water heat pump transfers heat into water.

That heated water can then circulate through:

Radiators.
Underfloor heating.
Fan-assisted convectors.
A hot-water cylinder.

This is the type most people mean when they refer to a domestic air source heat pump.

It can replace a gas, oil, LPG or electric boiler while allowing the property to retain a wet central-heating system.

Energy Saving Trust describes an air source heat pump as a system that transfers heat from the outside air to the water used in radiators, underfloor heating and a hot-water cylinder.

Air-to-Air Heat Pumps

An air-to-air heat pump transfers heat into the air inside the home.

It normally consists of:

An outdoor heat-pump unit.
One or more indoor fan units.
Refrigerant pipework.
Electrical connections.
Heating and cooling controls.

Rather than heating water for radiators, the indoor units blow warm air directly into the rooms.

Many air-to-air systems can also operate in reverse to provide cooling during warmer weather.

Energy Saving Trust estimates that a typical single-room air-to-air system may cost around £1,900, while a system serving a three-bedroom semi-detached home may cost approximately £3,700, although the actual price depends on the number of indoor units and installation complexity.

Air-to-Water or Air-to-Air?

An air-to-water and an air-to-air heat pump are both air source systems, but they provide very different forms of heating.

An Air-to-Water System May Be Suitable When:

The property already has radiators.
The homeowner wants wet central heating.
Domestic hot water is required.
Underfloor heating is being installed.
A boiler is being replaced.
Whole-house heating is required.
The home has space for a hot-water cylinder.

An Air-to-Air System May Be Suitable When:

The property has no wet heating system.
The home is relatively small or open plan.
Heating and cooling are both required.
External and internal fan units can be accommodated.
The property is a flat, annex or holiday home.
Domestic hot water will be provided separately.
The homeowner wants rapid room heating.

An air-to-air system does not normally provide domestic hot water, so the property may still require:

An immersion-heated cylinder.
A heat-pump water heater.
An electric water heater.
Another dedicated hot-water system.

The installer should establish whether the homeowner is looking for central heating, hot water, cooling or a combination of all three before recommending a system.

Why Install an Air Source Heat Pump?

Homeowners consider an air heat pump installation for several reasons.

The existing boiler may be old or unreliable. The property may be off the gas grid, undergoing a major renovation or being improved to reduce its dependence on fossil fuels.

Common reasons include:

Replacing a gas boiler.
Replacing an oil boiler.
Replacing an LPG boiler.
Removing direct electric heating.
Replacing storage heaters.
Creating heating for a renovated property.
Heating a new extension.
Providing heating and cooling.
Reducing direct use of fossil fuels.
Using electricity generated by solar panels.
Improving heating control.
Taking advantage of available grant funding.
Preparing a property for future energy changes.

A heat pump can be particularly attractive for a well-insulated home with a properly sized heating system.

However, the decision should be based on a complete assessment rather than the assumption that every home needs the same heat pump package.

Can an Air Source Heat Pump Heat an Older Home?

Air source heat pumps can be installed in both modern and older properties.

The age of the home is not the only deciding factor.

An older property may still be suitable where:

The heat loss has been properly calculated.
The radiators are correctly sized.
Draughts and major insulation defects are addressed.
The heating pipework is suitable.
The heat pump has been correctly selected.
The controls are properly commissioned.
The homeowner understands how the system should operate.

Ofgem advises that heat pumps perform best in a well-insulated property and that improving energy efficiency can reduce running costs and improve comfort. Its current Boiler Upgrade Scheme guidance also requires the installer to undertake a property heat-loss assessment before providing the final proposal.

This does not mean every old home must be completely rebuilt or brought up to new-build insulation standards.

It means the installer must understand how much heat the building loses and design the system to replace that heat.

A solid-wall Victorian house, rural cottage or converted barn may need:

Larger radiators.
Improved loft insulation.
Draught reduction.
Better heating controls.
Different heating zones.
Higher-output emitters.
Careful pipework design.

The design should reflect the real building rather than relying only on its number of bedrooms.

The Heat-Loss Calculation

A room-by-room heat-loss calculation is one of the most important stages of an ASHP installation.

The calculation considers how quickly each room loses heat through:

External walls.
Windows.
Doors.
Roofs.
Floors.
Ventilation.
Draughts.
Adjoining unheated spaces.

It also considers:

Room dimensions.
Wall construction.
Insulation.
Glazing.
Design outdoor temperature.
Required room temperature.

The result helps establish:

The total heat-pump output required.
The output needed from each radiator.
The appropriate heating flow temperature.
Whether the existing pipework can be retained.
Whether insulation improvements would be beneficial.
The expected annual energy performance.

Selecting a heat pump based only on the floor area or number of bedrooms is not a proper heating design.

A four-bedroom modern house may require less heat than a smaller but poorly insulated period property.

Correct Heat-Pump Sizing

A heat pump that is too small may struggle to maintain comfortable temperatures during cold weather.

A heat pump that is unnecessarily large may:

Cost more to purchase.
Require a larger electrical supply.
Cycle more frequently.
Operate less efficiently.
Create unnecessary noise.
Need a larger outdoor unit.

The selected appliance should be able to meet the calculated heating demand while also operating effectively during milder weather.

The design should consider both maximum and minimum output.

A properly sized system should not rely routinely on an electric immersion heater or backup heater to compensate for an inadequate heat pump.

Backup heating may be included for specific conditions, but it should not disguise an undersized or badly designed installation.

Heat Pumps and Lower Flow Temperatures

A traditional boiler may send water to the radiators at a relatively high temperature.

A heat pump normally operates more efficiently when the water flowing through the heating system is cooler.

Energy Saving Trust advises that reducing the flow temperature and allowing the heat pump to run more steadily can improve efficiency and reduce running costs.

This does not mean the home should feel cold.

It means the radiators or underfloor heating should be designed to provide the required room temperature using a greater surface area and a lower water temperature.

For example, instead of heating a small radiator to a very high temperature for a short period, a heat pump may supply a larger radiator with moderately warm water for longer.

The room can remain comfortable while the heat pump operates more efficiently.

Will the Radiators Need Replacing?

Not every air source heat pump installation requires every radiator to be replaced.

Some existing radiators may already be large enough.

Others may need to be upgraded because their output at the proposed lower flow temperature is insufficient.

The room-by-room design should identify:

Radiators that can be retained.
Radiators that need enlarging.
Rooms that need double-panel radiators.
Areas suitable for fan-assisted convectors.
Rooms that may benefit from underfloor heating.
Pipework that needs upgrading.
Radiators that are corroded or restricted.

Energy Saving Trust explains that larger radiators can heat rooms effectively using lower-temperature water, helping a heat pump operate more efficiently.

Changing a radiator is not evidence that the heat pump is unsuitable.

It is part of adapting the heat-distribution system to work efficiently with a different type of heat source.

The installer should explain which radiators need replacing and show how the decision relates to the heat-loss calculation.

Heating Pipework

The heating pipework must carry enough water to distribute heat around the property.

Older systems may contain:

Narrow microbore pipes.
Long restricted runs.
Poorly arranged extensions.
Blockages.
Sludge.
Unbalanced circuits.
Inadequate pumps.
Pipes that are difficult to access.

Microbore pipework does not automatically prevent a heat-pump installation, but it needs to be properly assessed.

The installer should consider:

Internal pipe diameter.
Required water flow.
Pressure loss.
Circuit length.
Number of radiators.
Heating zones.
Pump requirements.
Noise.
Future maintenance.

Some pipework may be retained while other sections require replacement or alteration.

Simply connecting a heat pump to an existing boiler system without checking flow rates can lead to poor performance.

Underfloor Heating

Wet underfloor heating can work particularly well with an air source heat pump because it provides a large heating surface and can operate using relatively low water temperatures.

It may be suitable for:

New homes.
House extensions.
Kitchen and dining refurbishments.
Ground-floor renovations.
Well-insulated rooms.
Properties where radiators would obstruct furniture layouts.

A wet underfloor-heating installation may include:

Insulation beneath the pipes.
Heating loops.
A manifold.
Pumps.
Mixing controls.
Room thermostats.
Separate heating zones.
Suitable floor finishes.

The system should be designed around the floor construction and heat loss.

Underfloor heating installed without adequate insulation beneath it can waste heat into the structure below.

A property may also use a combination of underfloor heating downstairs and radiators upstairs.

Domestic Hot Water

An air-to-water heat pump will normally provide domestic hot water through a storage cylinder.

Unlike a gas combi boiler, it does not usually produce large quantities of instantaneous hot water directly from the appliance.

The cylinder should be sized around:

The number of occupants.
The number of bathrooms.
Bath sizes.
Shower use.
Simultaneous demand.
Available cylinder space.
Reheat time.
Incoming water pressure and flow.

Heat-pump cylinders often need a larger heat-exchanger coil than a conventional boiler cylinder so that heat can be transferred effectively at lower temperatures.

The existing cylinder may therefore need replacing even if it appears to be in reasonable condition.

Heat pumps generally operate most efficiently at lower water temperatures. A correctly designed system may periodically raise the cylinder temperature through a sterilisation cycle, sometimes with assistance from an immersion heater.

Where Can the Hot-Water Cylinder Go?

Possible cylinder locations include:

An airing cupboard.
A utility room.
A plant room.
A garage.
A large kitchen cupboard.
A suitable loft space.

The proposed location should consider:

The weight of the full cylinder.
Access for installation.
Access for future replacement.
Safety-discharge pipework.
Distance to taps and showers.
Heat loss from long pipe runs.
Structural support.
Maintenance access.
Available height.
Electrical supplies.

Removing an old combi boiler and installing an air-to-water heat pump may mean reintroducing a hot-water cylinder into a home where the previous cylinder was removed.

This space requirement should be discussed at the beginning of the project.

Outdoor Unit Position

The outdoor unit collects heat from the surrounding air.

Its position can affect:

Performance.
Noise.
Appearance.
Maintenance access.
Air circulation.
Planning compliance.
Condensate disposal.
Neighbouring properties.

Possible positions include:

Beside an external wall.
In a side passage.
In a rear garden.
On a suitable flat roof.
On a purpose-designed support frame.
On an external wall using approved brackets.

The unit needs sufficient open space around it so that air can enter and leave freely.

It should not be boxed into a tight enclosure or hidden behind dense planting that restricts airflow.

The installer should also avoid positions where cold discharge air is directed towards:

A doorway.
A frequently used patio.
A narrow enclosed passage.
A neighbouring window.
Delicate plants.
Another heat pump.

A short, convenient pipe route should be balanced against noise, appearance and planning considerations.

Heat-Pump Noise

Modern heat pumps are designed for residential use, but they are not silent.

The outdoor unit contains a fan and compressor.

The actual sound experienced by a homeowner or neighbour depends on:

The selected model.
Distance from the unit.
Unit output.
Fan speed.
Surrounding walls.
Hard reflective surfaces.
Mounting arrangements.
Operating conditions.
Background noise.
Whether the unit is in a narrow passage.

A poorly selected position can amplify noise through reflection or vibration.

The installer should assess:

Distance from neighbouring windows.
Distance from bedrooms.
Boundary positions.
Potential sound reflection.
Anti-vibration supports.
Night-time operating modes.
The MCS planning noise calculation.

The quietest available unit can still cause a problem if it is badly positioned.

The design should consider the homeowner and the neighbouring property before installation begins.

Planning Permission

Many domestic air source heat pump installations in England can be completed under permitted development rights, provided the relevant limits and conditions are met.

Current requirements include compliance with the applicable MCS planning standard. Additional restrictions can apply to listed buildings, flats, conservation areas, World Heritage Sites and properties where permitted development rights have been removed.

Planning rules differ across England, Wales, Scotland and Northern Ireland.

Before installing the outdoor unit, the homeowner and installer should check:

The type of property.
The proposed unit position.
The number of outdoor units.
Unit dimensions.
Distance from boundaries.
Noise calculations.
Whether the property is listed.
Whether it is in a conservation area.
Whether an Article 4 Direction applies.
Whether planning conditions restrict external equipment.
Whether the freeholder’s consent is required.

Flats and shared buildings can have more restricted permitted development rights, making planning permission more likely to be required.

A homeowner should not assume that a heat pump can be installed anywhere simply because the equipment is low carbon.

Listed Buildings and Conservation Areas

An air source heat pump can sometimes be installed at a listed building or within a conservation area, but the position and visual impact require greater care.

Possible considerations include:

Visibility from the street.
Effect on the character of the building.
Fixing equipment to historic fabric.
Pipe penetrations.
External trunking.
Listed building consent.
Noise.
Screening.
Alternative locations.
Archaeological implications of ground works.

A less visible position may be preferred, but it must still provide suitable airflow and servicing access.

Screening may help reduce visual impact, although it must not restrict airflow or create a noise enclosure.

Planning or heritage advice should be obtained before equipment is ordered where consent may be required.

Electrical Supply

An air source heat pump creates a significant electrical load.

The installer and electrician may need to assess:

The incoming electricity supply.
Main service fuse.
Consumer unit.
Available electrical capacity.
Cable routes.
Circuit protection.
Isolation.
Earthing and bonding.
Existing electric showers.
Electric vehicle chargers.
Induction cooking.
Solar panels.
Battery storage.
Immersion heaters.
Backup heating elements.
Whether approval from the electricity network operator is required.

The property may need:

A new dedicated circuit.
Consumer-unit alterations.
A larger supply cable.
A main-fuse upgrade.
Load-management equipment.
Electrical network notification.
Three-phase electricity in unusual high-load cases.

The electrical requirements should be established before the installation quotation is accepted.

A relatively attractive heat-pump price can increase significantly if major electrical upgrading has been omitted.

Refrigerant and Water Connections

Air-to-water heat pumps are commonly supplied in different configurations.

Monobloc Heat Pumps

A monobloc unit contains the main refrigerant circuit within the outdoor unit.

Water pipes then connect the outdoor unit to the heating system inside the home.

External water pipes must be:

Properly insulated.
Protected from physical damage.
Designed to limit heat loss.
Protected against freezing.
Kept as short as reasonably practical.

Split Heat Pumps

A split heat pump has an outdoor and indoor refrigerant unit connected by refrigerant pipework.

This can reduce the amount of heating water located outside, but the refrigerant work requires appropriately qualified personnel.

The installer should explain:

Which type is proposed.
Why it suits the property.
How freezing will be prevented.
Where the indoor equipment will be located.
How the external pipes will be protected.
What maintenance will be required.

Buffer Vessels and Volumisers

Some heat-pump systems include a buffer vessel or volumiser.

These components may help provide:

Sufficient water volume.
Stable circulation.
Hydraulic separation.
Support during defrost cycles.
Reduced short cycling.
Separation of heating zones.

However, they should not be included automatically without a design reason.

An unnecessary buffer vessel can:

Occupy space.
Increase heat loss.
Add pumps and controls.
Increase installation cost.
Make the system more complicated.

The installer should explain why any buffer, volumiser, low-loss header or additional pump is required.

The design should remain as simple as possible while meeting the technical needs of the system.

Heating Controls and Weather Compensation

Heat pumps often work best when allowed to maintain a steady indoor temperature rather than being switched on and off in the same way as an old boiler.

Controls may include:

Weather compensation.
Room thermostats.
Heating curves.
Individual heating zones.
Thermostatic radiator valves.
Hot-water timing.
Holiday settings.
Mobile app control.
Smart electricity-tariff integration.
Solar and battery coordination.

Weather compensation adjusts the heating-water temperature according to outdoor conditions.

When the weather is mild, the system may supply cooler water. When the weather becomes colder, it gradually raises the flow temperature.

This can help the heat pump operate more efficiently than repeatedly delivering water at the highest possible temperature.

Energy Saving Trust recommends steady operation, lower flow temperatures and appropriate heating-curve adjustments to improve efficiency.

The controls should be properly commissioned and clearly explained to the homeowner.

Living With a Heat Pump

A heat pump may operate differently from the boiler it replaces.

A boiler often produces a short burst of very hot water and then turns off.

A heat pump normally works more gradually and may operate for longer periods using lower-temperature water.

Homeowners may notice that:

Radiators feel warm rather than extremely hot.
The heating operates for longer.
Indoor temperatures remain steadier.
Large overnight temperature reductions are less suitable.
Weather compensation changes the flow temperature automatically.
The outdoor unit occasionally performs a defrost cycle.
Hot-water reheating may take longer than with a powerful boiler.

These differences are not necessarily signs of poor performance.

The important test is whether the property reaches and maintains the required temperature efficiently.

The installer should explain how to operate the system before leaving the property.

Air Source Heat Pump Installation Cost

The air source heat pump installation cost depends on the property and the amount of work required to adapt its heating system.

Energy Saving Trust currently gives a typical air source heat pump installation cost of around £11,000. Actual quotations can be lower or substantially higher depending on the size of the property and the work required to the radiators, cylinder, pipework and electrical supply.

The price may include:

Heat-loss calculations.
Heat-pump design.
The outdoor unit.
Indoor hydraulic equipment.
A hot-water cylinder.
Radiator replacements.
Pipework alterations.
Electrical work.
Heating controls.
A system filter.
System cleaning.
Condensate drainage.
Equipment bases or brackets.
Commissioning.
MCS certification.
Building Regulations notification.
Removal of the old boiler or heating equipment.

A small, well-insulated property with suitable radiators may cost less.

A large period home requiring extensive radiator, cylinder, pipework and electrical changes may cost considerably more.

What Affects Air Source Heat Pump Installation Cost?

Property Size and Heat Loss

A larger or poorly insulated home may require a larger heat pump and more extensive radiator upgrades.

Radiator Replacement

Some existing radiators may be retained, while others may need replacing with larger or higher-output models.

Hot-Water Cylinder

A new heat-pump-compatible cylinder can add significantly to the cost.

Heating Pipework

Restricted, contaminated or badly arranged pipes may require alterations.

Electrical Work

Costs can increase where the consumer unit, supply cable or main fuse needs upgrading.

Outdoor Unit Position

A simple ground-mounted unit close to the house may cost less than a roof-mounted or difficult-access installation.

Planning and Design

Listed buildings, flats and sensitive locations may require additional planning, acoustic or heritage work.

Removal of Existing Heating

The cost may include removal of:

A gas boiler.
An oil boiler.
An oil tank.
An LPG boiler.
Storage heaters.
Redundant cylinders.
Existing flues.

Building Work

Additional work may include:

Wall openings.
New equipment bases.
Cupboard alterations.
Fire stopping.
Making good.
Drainage.
Structural supports.

A quotation should clearly separate the heat-pump equipment from all associated heating, electrical and building work.

Boiler Upgrade Scheme Grants

Property owners in England and Wales may be able to receive financial support through the Boiler Upgrade Scheme when replacing an eligible fossil-fuel heating system.

As of 16 July 2026, the standard grant is:

£7,500 towards an eligible air-to-water heat pump.
£2,500 towards an eligible air-to-air heat pump.

From 21 July 2026, eligible off-gas-grid properties replacing an oil or LPG heating system with an air-to-water heat pump can qualify for an increased £9,000 grant, currently scheduled to apply until 31 March 2027.

The Boiler Upgrade Scheme is installer-led.

The homeowner chooses an MCS-certified installer, and the installer manages the grant application. The grant should be deducted from the quotation and final invoice rather than paid to the homeowner as cash.

Eligibility conditions apply, and funding arrangements differ in Scotland and Northern Ireland.

The grant should never be assumed until the installer has checked eligibility and the application has been accepted.

MCS-Certified Heat-Pump Installation

Homeowners seeking a Boiler Upgrade Scheme grant must use an MCS-certified installer and eligible equipment.

MCS sets installation and product standards for small-scale renewable technologies, including heat pumps. The current installation standard covers the installation, setting to work and commissioning of heat-pump systems.

An MCS-certified installer should provide:

A system design.
Heat-loss calculations.
An installation proposal.
A performance assessment.
Commissioning.
An MCS certificate.
Handover information.
Consumer-protection arrangements.

Ofgem advises homeowners to obtain quotations from multiple MCS-certified installers before committing to a project.

MCS certification is not simply a badge attached to the heat-pump manufacturer.

The installation business itself must hold the relevant certification for the work.

Air Source Heat Pump Installation Near Me

A homeowner searching for air source heat pump installation near me needs more than the nearest plumber or boiler engineer.

Heat-pump installation requires knowledge of:

Building heat loss.
Heat-pump sizing.
Radiator output.
Heating flow temperatures.
Hot-water cylinders.
Hydraulic design.
Electrical supplies.
Refrigerant systems where applicable.
Outdoor-unit positioning.
Acoustic assessment.
Planning requirements.
Control commissioning.
MCS standards.

A local installer may provide:

Familiarity with local housing types.
Knowledge of local winter conditions.
Easier access for surveys.
Reduced travelling costs.
Faster aftercare.
Familiarity with local planning authorities.
Convenient servicing.

However, distance should not be the only consideration.

A nearby installer offering a standard package without room-by-room design may be less suitable than a specialist who properly assesses the property.

MCS provides an official search facility for locating certified installers by area.

APN Boilers aims to help homeowners connect with an appropriate heat-pump professional based on the property and project requirements as well as location.

Air-to-Air Heat Pump Installation

An air-to-air heat pump installation uses one or more indoor fan units to distribute warm or cool air.

The outdoor unit collects or rejects heat, depending on whether the system is operating in heating or cooling mode.

A typical system may include:

An outdoor condenser unit.
One or more indoor wall, floor or ceiling units.
Refrigerant pipes.
Condensate drainage.
Electrical supplies.
Remote or smart controls.

Single-Split Systems

A single outdoor unit serves one indoor unit.

This may be suitable for:

A principal living room.
A home office.
A studio flat.
An annex.
A garden room.
A holiday let.

Multi-Split Systems

One outdoor unit serves several indoor units.

This can provide heating and cooling to multiple rooms, although pipe routes and individual room requirements must be carefully planned.

Ducted Systems

A concealed indoor unit distributes air through ducts and grilles.

This can create a less visible installation but normally requires ceiling, loft or service space.

Air-to-Air Heat Pump Installation Cost

Energy Saving Trust currently estimates an air-to-air installation at around:

£1,900 for a system serving one room.
£3,700 for a system serving a typical three-bedroom semi-detached home.

Actual prices will vary according to the number of indoor units, pipe lengths, access, electrical work and the amount of making good required.

The cost may increase where:

Several indoor units are required.
Pipe routes are long or concealed.
Scaffolding is needed.
The outdoor unit is roof-mounted.
A condensate pump is required.
The electrical supply needs upgrading.
A ducted system is installed.
Planning permission is required.
Decorative making good is extensive.

The quotation should explain whether the system provides heating only or heating and cooling.

It should also identify how domestic hot water will be provided.

Air-to-Air Heat Pumps in Flats

Air-to-air heat pumps can work well in flats because they do not require radiators, heating pipes or a hot-water cylinder.

Potential benefits include:

Compact indoor units.
Heating and cooling.
Rapid room heating.
No wet central-heating system.
Independent room control.
Suitability for smaller properties.

However, flats can present complications:

Freeholder consent.
Lease restrictions.
Planning requirements.
External appearance.
Outdoor-unit noise.
Fixing equipment to communal walls.
Refrigerant pipes through common parts.
Condensate drainage.
Electrical capacity.
Fire stopping around service penetrations.

The homeowner should obtain any required consent before installation begins.

Heat Pumps and Solar Panels

Solar panels can generate some of the electricity used by an air source heat pump.

This may help reduce imported electricity, particularly during daylight hours.

However, the greatest heating demand normally occurs during colder months when solar generation is lower.

A solar-and-heat-pump system should therefore consider:

Solar-array size.
Winter generation.
Heat-pump demand.
Battery capacity.
Hot-water timing.
Smart tariffs.
Household electricity use.
Electric vehicle charging.
Export payments.
Energy-management controls.

Solar panels can support a heat pump, but they should not be presented as providing free winter heating.

The design should use realistic generation and consumption assumptions.

Heat Pumps and Battery Storage

Battery storage may allow electricity generated during the day or purchased at a lower tariff to be used later.

Potential benefits include:

Using more solar electricity within the home.
Reducing peak-rate imports.
Supporting hot-water production.
Coordinating heating with time-of-use tariffs.
Reducing demand during expensive periods.

However, domestic batteries have limited storage capacity compared with the energy needed to heat a home during cold weather.

The battery, heat pump, tariff and controls should be considered as one energy system.

Heat-Pump Running Costs

Heat-pump running costs depend on:

The property’s heat loss.
Heat-pump efficiency.
Heating flow temperature.
Electricity tariff.
Indoor temperature.
Heating hours.
Hot-water demand.
Weather.
Control settings.
Radiator sizing.
Use of backup heating.
Solar and battery contribution.

A heat pump will not automatically cost less to operate than every boiler.

Energy Saving Trust notes that running-cost savings depend heavily on the heating system being replaced.

Replacing direct electric heating, an inefficient oil system or some LPG systems may produce different results from replacing a newer mains-gas boiler.

The quotation should include a realistic estimate of expected electricity consumption and bill impact.

The installer should clearly state:

The assumed heat demand.
Expected seasonal efficiency.
Proposed flow temperature.
Electricity price assumptions.
Existing fuel-use assumptions.
Whether backup heating is included.
How hot-water consumption has been estimated.

What Should an ASHP Installation Quote Include?

A detailed quote should identify:

Heat-pump manufacturer and model.
Maximum and minimum output.
Design outdoor temperature.
Room-by-room heat-loss calculation.
Proposed heating flow temperature.
Expected seasonal performance.
Radiators being retained.
Radiators being replaced.
Heating-pipe alterations.
Hot-water cylinder.
Buffer vessel or volumiser.
Pumps and valves.
Heating controls.
Outdoor-unit position.
Noise assessment.
Equipment base or brackets.
Condensate arrangements.
External-pipe insulation.
Electrical work.
Consumer-unit alterations.
Main-fuse requirements.
Removal of existing equipment.
Making good.
Planning responsibility.
Building Regulations notification.
MCS certification.
Boiler Upgrade Scheme grant.
Final homeowner contribution.
Warranty.
Commissioning.
Servicing requirements.
VAT.
Payment terms.
Exclusions.

Avoid accepting a quotation that simply states “supply and install air source heat pump.”

Without the full design, it is impossible to understand whether the system will heat the property properly.

Questions to Ask a Heat-Pump Installer

Before accepting a quotation, ask:

Are you MCS certified for heat-pump installation?
Will you complete a room-by-room heat-loss calculation?
What outdoor design temperature have you used?
Why have you selected this heat pump?
What is its minimum and maximum output?
What heating flow temperature is proposed?
Which radiators need replacing?
Can the existing pipework provide the required flow?
Do we need a new hot-water cylinder?
What hot-water capacity is proposed?
Why is a buffer vessel included?
Where will the outdoor unit be installed?
Has a noise assessment been completed?
Is planning permission required?
Is the electrical supply suitable?
Will the consumer unit or main fuse need upgrading?
How will external pipes be protected from freezing?
What will the estimated annual electricity use be?
What seasonal efficiency have you assumed?
Are we eligible for a Boiler Upgrade Scheme grant?
Is the grant deducted from the quoted price?
What MCS and Building Regulations documents will we receive?
What warranty is included?
Who provides future servicing and aftercare?
What work is excluded from the quotation?

An experienced installer should be able to explain the design in terms the homeowner understands.

Air Source Heat Pump Installation During Home Improvements

A major extension, refurbishment or loft conversion can be an ideal time to install an air source heat pump.

Floors, walls and ceilings may already be open, making it easier to:

Replace heating pipes.
Install larger radiators.
Provide underfloor heating.
Create a cylinder cupboard.
Upgrade insulation.
Install electrical supplies.
Form external pipe routes.
Coordinate drainage.
Create heating zones.
Remove an old boiler and flue.

The heat pump should be designed around the completed property rather than the home as it existed before the improvements.

The design must include:

New rooms.
Changed room sizes.
Improved insulation.
New glazing.
Additional bathrooms.
Underfloor heating.
Revised occupancy.
Future heating zones.

Installing a heat pump before the final building design has been established can result in an incorrectly sized system.

The APN network brings together more than 40 years of experience in homes, heating layouts, building projects and property improvement.

This helps ensure that the heating system is considered alongside the building work rather than as a separate last-minute decision.

Commissioning the Heat Pump

Commissioning is essential to the performance of an air source heat pump.

The installer should not simply switch on the unit and leave it operating on factory settings.

Commissioning may include:

Checking system water flow.
Setting pumps.
Balancing radiators.
Checking heating zones.
Setting the weather-compensation curve.
Setting maximum flow temperatures.
Programming hot-water schedules.
Testing immersion or backup heaters.
Checking outdoor-unit operation.
Testing defrost cycles.
Checking electrical protection.
Testing controls.
Confirming cylinder operation.
Checking external-pipe insulation.
Recording system settings.
Completing MCS documentation.

The homeowner should receive an explanation of:

How the heating operates.
How to adjust the room temperature.
How weather compensation works.
How to set hot-water times.
What a defrost cycle looks like.
How to use holiday mode.
What to do if a fault appears.
When the system should be serviced.
Who to contact for support.

Good commissioning can make the difference between an efficient system and one that uses more electricity than necessary.

Servicing and Maintenance

Air source heat pumps generally require less combustion-related maintenance than gas, oil or LPG boilers, but they still need inspection and servicing.

Maintenance may include:

Cleaning the outdoor heat exchanger.
Removing leaves and debris.
Checking airflow.
Inspecting fan operation.
Checking refrigerant components.
Checking water pressure.
Cleaning filters.
Checking system water quality.
Inspecting pumps and valves.
Checking electrical connections.
Testing controls.
Reviewing performance data.
Checking cylinder and safety components.
Inspecting external-pipe insulation.

The outdoor unit should remain clear of:

Leaves.
Dense vegetation.
Stored materials.
Snow accumulation.
Fences or enclosures that restrict airflow.

The manufacturer’s maintenance and warranty requirements should be followed.

Air Source Heat Pump Installation Through APN Boilers

APN Boilers helps homeowners find experienced professionals for air source heat pump installation, ASHP installation and air-to-air heat pump systems throughout the UK.

The APN network is supported by more than 40 years of experience in homes, heating design, building work and property improvement.

Our approach considers the complete installation, including:

The size and construction of the property.
Room-by-room heat loss.
Insulation and draughts.
Heat-pump type and output.
Radiator sizes.
Underfloor heating.
Heating pipework.
Hot-water demand.
Cylinder requirements.
Electrical capacity.
Outdoor-unit location.
Noise and neighbouring properties.
Planning requirements.
Heating controls.
Solar panels and battery storage.
Boiler Upgrade Scheme eligibility.
Installation costs.
Expected running costs.
Future extensions and home improvements.
The homeowner’s budget.

Whether you need an air-to-water heat pump for a family home, an air-to-air heat pump for a flat or a complete low-carbon heating system for a renovated property, the project should begin with a proper assessment and heating design.

A carefully designed air source heat pump installation can provide dependable heating, efficient operation and improved control without burning gas, oil or LPG at the property.

The key is to select the correct system, adapt the radiators and pipework where required and commission the controls around the way the home is actually used.

Tell APN Boilers about your property, existing heating system and planned improvements. We will help connect you with an experienced heat-pump professional who can assess the heat loss, radiators, hot-water requirements and electrical supply before recommending the right air source heat pump installation for your home.

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