Choosing the right heat pump is important.

Choosing the company responsible for designing and installing it is just as important.

A heat pump should not simply be fitted outside your home, connected to the existing heating system and left to run.

It forms part of a complete heating system.

The heat pump, radiators, pipework, hot water, controls and the heating requirements of the property all need to work together.

That means the quality of the assessment, calculations, design, installation and commissioning can have a significant effect on how the finished system performs.

So how do you compare heat pump installers?

Price will naturally be part of the decision, but it should not be the only question you ask.

Here are the things worth finding out before choosing who will install your heat pump.

This is one of the first things to check.

MCS is an important standards organisation for small scale renewable energy and heating installations in the UK.

For homeowners, choosing an MCS certified installer provides reassurance that the company is working within recognised industry standards.

MCS certification can also be important when accessing certain financial support for renewable heating.

You can check an installer’s certification through the MCS website.

Renewable Heat is MCS certified and can explain how the certification relates to your installation and any funding you may be considering.

MCS is not the only credential worth considering.

Depending on the company and the work being completed, installers may also belong to recognised consumer protection schemes and trade organisations.

Renewable Heat’s memberships include RECC and SNIPEF.

The Renewable Energy Consumer Code, or RECC, sets consumer protection standards for businesses selling or leasing renewable energy systems to domestic customers.

SNIPEF represents plumbing and heating businesses in Scotland and Northern Ireland.

Credentials alone cannot tell you everything about an installer.

But they provide useful information about the standards and professional frameworks the company works within.

A reputable installer should be comfortable explaining what its certifications and memberships mean.

This is where the technical conversation should begin.

Before recommending a heat pump, the installer needs to understand how much heat your property requires.

That means calculating heat loss.

Your home continuously loses heat through areas such as:

• Walls
• Windows
• Doors
• Roofs
• Floors
• Ventilation

How much heat is lost depends on the construction and condition of the property.

An older stone property can behave very differently from a modern house.

An extension may also have different insulation levels from the original building.

The heating system needs to replace that lost heat so the rooms can maintain the required indoor temperature.

This is why choosing a heat pump should begin with the property rather than a particular model.

Ask this question directly.

A proper heat pump design should consider heat loss room by room rather than relying only on the total floor area or number of bedrooms.

Different rooms have different heating requirements.

A large living room with several external walls and large windows may lose considerably more heat than a small internal bedroom.

The calculation should consider factors including:

• Room dimensions
• Wall construction
• Insulation
• Windows and glazing
• Floors
• Roofs or ceilings
• Ventilation
• Required indoor temperatures
• Relevant outdoor design conditions

The information can then be used to determine how much heat each room needs and the overall heating requirement of the property.

This forms the foundation for selecting the heat pump and assessing the radiators.

Do not be afraid to ask why a particular size has been recommended.

Heat pump output is measured in kilowatts, but the correct output cannot reliably be determined from the number of bedrooms or floor area alone.

The recommendation should relate to the calculated heating requirements of your property.

Bigger is not automatically better.

An oversized heat pump can cost more than necessary and may be more prone to excessive cycling if its output cannot reduce sufficiently when heating demand is low.

An undersized system can create different problems if it cannot meet the property’s heating requirements under the conditions it was designed for.

The objective is therefore not to choose the largest heat pump possible.

It is to choose an appropriate one.

If an installer cannot explain how they arrived at the recommended size, ask for more information.

This is another useful question.

The rated output of the boiler being removed should not simply determine the size of the replacement heat pump.

Boilers and heat pumps operate differently.

Combi boilers in particular can have relatively high rated outputs because they need to provide hot water quickly.

That number does not necessarily represent the space heating requirement of the property.

The proposed heat pump should therefore be based on calculated heat demand rather than simply matching the number printed on the boiler.

Installing a heat pump does not automatically mean replacing every radiator.

But the radiators do need to be assessed.

Heat pumps generally operate at lower water temperatures than traditional boilers.

A radiator that works effectively with hotter boiler water may provide less heat at the lower water temperature proposed for a heat pump system.

The installer should therefore determine whether each radiator can provide enough heat for its room.

Some may already be suitable.

Others may need upgrading.

Ask the installer to explain:

Which radiators can remain?

Which radiators need changing?

What output does each room require?

What operating temperature has the system been designed around?

You should be given a reason for the recommended changes.

Not necessarily.

This is where a room by room assessment becomes particularly useful.

If an existing radiator can provide the required output at the proposed heating water temperature, it may be able to stay.

There is little benefit in replacing suitable equipment simply because a heat pump is being installed.

Equally, being told that none of your radiators need changing without the appropriate calculations should prompt further questions.

A good design identifies what can stay and what genuinely needs upgrading.

Radiators are only one part of the existing heating system.

The pipework needs to be considered too.

A heat pump system needs sufficient water flow to distribute heat around the property.

Some existing pipework may already be suitable.

In other homes, restricted or altered sections may need attention.

This can be particularly important in retrofit projects where the heating system has changed over many years.

An extension may have been added.

Radiators may have moved.

Heating zones may have changed.

Previous boiler installations may have altered sections of the system.

Ask whether the existing pipework has been considered as part of the design and whether any changes are included in the quotation.

If you currently have a combi boiler, this is particularly important.

A heat pump installation will commonly use a hot water cylinder.

The cylinder needs to be appropriately sized around household requirements.

A smaller household with one bathroom will have different requirements from a busy family home with several bathrooms and higher hot water use.

Ask the installer:

What cylinder are you recommending?

Why is that size appropriate?

Where will it be installed?

How will the system provide the amount of hot water our household uses?

Domestic hot water should be part of the design conversation from the beginning.

This is a more technical question, but it is worth asking.
Heat pump performance is influenced by the heating water temperature the system needs to produce.
In general, lower heating water temperatures can support more efficient heat pump operation, provided the radiators or underfloor heating can still deliver the heat the rooms require.
That is why flow temperature cannot be considered separately from radiator sizing and heat loss.
The installer should have a clear design approach rather than simply choosing a heat pump and hoping the existing heating system will accommodate it.

Controls matter.

Heat pumps generally work differently from boilers and can benefit from maintaining steadier temperatures rather than repeatedly heating the home in short bursts.

Ask how the proposed system will be controlled.

This could include weather compensation, which allows the heating water temperature to respond to changing outdoor conditions.

When outdoor temperatures are milder, the property requires less heat.

The system may therefore be able to operate with a lower water temperature.

When conditions become colder, the required water temperature can increase.

The important thing is that the controls are designed and configured around the property.

The location of an air source heat pump should be considered carefully.

It needs suitable airflow and access for installation and future maintenance.

The installer should also consider the relationship between the proposed location and:

• Windows
• Doors
• Outdoor seating areas
• Boundaries
• Neighbouring properties
• Pipework routes
• Access
• Relevant planning and noise requirements

The easiest place to physically install the unit is not necessarily the best location for the finished system.

Ask why the proposed position has been selected.

This is one of the most important questions when comparing installers.

Do not compare only the figure at the bottom of the page.

Compare what you are actually getting.

Depending on the property, a complete quotation could include:

• Heat pump
• Hot water cylinder
• Radiator upgrades
• Pipework alterations
• Electrical work
• Heating controls
• Outdoor unit installation
• System design
• Installation labour
• Commissioning
• Handover
• Aftercare

If one quote is considerably cheaper, establish why.

It might represent excellent value.

Or it might simply exclude work that another installer has included.

A quotation is only genuinely cheaper if you are comparing the same scope of work.

If grant or loan support is available, make sure you understand how it has been presented.

Ask to see the complete project cost before funding and how any eligible support changes the amount you may ultimately pay.

For homeowners in Scotland, Home Energy Scotland is the appropriate place to check current information about available financial support and eligibility.

Funding schemes, eligibility requirements and available amounts can change.

It is therefore important to check the current official guidance rather than relying solely on an old advert or headline price.

You should understand:

The complete project cost

What funding you may be eligible for

Whether funding has been confirmed

What you are expected to contribute

That makes quotations easier to understand and compare.

It is reasonable to ask who will be carrying out the work at your property.

You are not only buying equipment.

You are trusting a company to make significant changes to your heating system and, potentially, your hot water, electrical installation and controls.

Ask about the installation team and how the work is managed.

If subcontractors are involved, you can also ask who remains responsible for the complete project and who you contact if there is a problem.

Clear responsibility is valuable during both installation and aftercare.

Accreditations matter.

Experience matters too.

Retrofitting a heat pump into an existing home can be more complicated than working with a heating system designed from the beginning for a newly built property.

Existing homes can contain:

• Older radiators
• Altered pipework
• Several heating zones
• Different insulation levels
• Extensions
• Underfloor heating
• Multiple bathrooms
• Previous heating system modifications
• Existing renewable technologies

None of these automatically make the property unsuitable.

But the installer needs to recognise them and design accordingly.

Ask whether the company has experience with homes similar to yours.

This question is particularly useful if your property has been extended or renovated.

For example, you might have radiators in the original part of the house and underfloor heating in an extension.

Perhaps you have several thermostats or heating zones.

You may already have solar thermal, solar PV or another energy system.

A good installer should be interested in understanding those complications.

They should not be trying to make your property fit a standard package.

A good retrofit is not about replacing the maximum amount of equipment.

It is about identifying what the property needs.

Some existing radiators may be suitable.

Some pipework may be perfectly adequate.

Other components may genuinely need changing.

Ask the installer to explain both sides:

What can stay?

What needs changing?

Why?

This can help you understand the design and avoid unnecessary work.

Installing the equipment is not the final step.

The heating system needs to be commissioned.

This is when the installer checks that the completed system is operating as intended.

Commissioning can involve:

• Checking system operation
• Reviewing water flow
• Balancing the heating system
• Configuring controls
• Testing domestic hot water
• Checking temperatures
• Confirming the heat pump is operating correctly

Ask what commissioning is included and what checks will be completed before handover.

A new heating system should not be handed over without explanation.

Before the installation is complete, you should understand the basic controls and how the system is intended to operate.

Ask whether the installer will explain:

• Heating controls
• Temperature settings
• Hot water controls
• Heating schedules where relevant
• Weather compensation
• Basic system information
• What to do if something appears wrong
• Who to contact for support

You should not need to become a heating engineer.

But you should feel comfortable using your own heating system.

The relationship with the installer should not necessarily end when the heat pump is switched on.

Ask what happens afterwards.

Does the company provide servicing?

Can it carry out repairs?

Is technical support available?

Who do you contact if you have a question six months later?

Does the installer offer remote monitoring where suitable?

These questions matter because a heat pump is expected to remain part of your home for many years.

Renewable Heat provides repairs, servicing and maintenance alongside its installation work.

Annual servicing is recommended, and remote monitoring may also be available for suitable systems.

This sounds simple, but it is important.

Your first heating season with a heat pump may be different from what you were used to with a boiler.

You might have questions about controls.

You might want to understand a setting.

A room may not feel quite as expected.

Being able to contact the installer and discuss the system can make a significant difference.

Ask what support is available and how you access it.

Not every homeowner needs a wider retrofit plan.

But if you are considering several home improvements, it can be useful to understand how they fit together.

You might be thinking about:

• Insulation
• Ventilation
• Solar PV
• Battery storage
• Underfloor heating
• An extension
• Wider renovation work

These decisions can interact.

For example, significant insulation improvements can affect heat loss, which can influence heating requirements.

Renewable Heat’s approach begins with understanding the property and designing the heating system around it.

For homeowners considering a wider retrofit journey, independent whole home planning can also help establish which improvements should happen first.

No.
An air source or ground source heat pump can operate without solar PV or battery storage.
These technologies can, however, become part of a wider home energy system.
Solar PV can generate electricity at the property.
Battery storage can store electricity for later use.
Renewable Heat can also design integrated heat pump, solar and battery systems where appropriate.
You do not need to install everything at once.
A good installer should be able to discuss future options without making unnecessary technologies a condition of installing the heat pump.

No single sign automatically means an installer is unsuitable.

But there are situations where it is sensible to ask more questions.

Be cautious if:

• A heat pump is recommended before the property has been properly assessed
• The proposed size appears to be based only on floor area or bedroom count
• The installer simply matches the output of your existing boiler
• There is no clear room by room heat loss calculation
• Nobody has considered your radiators
• Pipework is ignored
• Hot water requirements have not been discussed
• You cannot get a clear explanation of what the quote includes
• The installer cannot explain why particular changes are required
• You are pressured to make a quick decision
• There is little information about commissioning
• Nobody can explain what happens after installation

A good installer should not be uncomfortable with detailed questions.

Those questions are part of making an informed decision.

Homeowners understandably spend time researching heat pump manufacturers and models.

That is useful.

But even high quality equipment depends on the system around it.

The heat pump needs to be appropriately sized.

The radiators need to provide enough heat.

The pipework needs to support the required flow.

Hot water needs to meet household demand.

The controls need to be configured properly.

And the complete system needs to be commissioned correctly.

That is why the installer matters so much.

Renewable Heat has more than 20 years of experience designing and installing home energy systems, including air source heat pumps and ground source heat pumps.

Our approach begins with understanding the property rather than selecting a standard package.

We assess the heating requirements, design the wider system, explain what needs to change and provide support beyond installation.

A heat pump is a significant investment in your home.

You should understand what you are buying.

Ask how the heat loss was calculated.

Ask why that heat pump size was selected.

Ask which radiators need changing.

Ask about the pipework.

Ask how hot water will work.

Ask what the quotation includes.

Ask what happens during commissioning.

Ask what support you receive afterwards.

And if something does not make sense, ask again.

A good installer should be willing to explain the system they are proposing and why it is appropriate for your home.

Your heat pump should be designed around your property, not sold as a standard package.

Call 0330 022 0480 or email sales@renewableheat.com to arrange a Home Assessment and discuss the right heating system for your property.