What does a gas or oil heating engineer need to do to become a heat pump installer?

Heat pumps have a major role to play in decarbonising home heating.

To create a healthier planet by reducing carbon emissions from home heating, the UK needs to be installing around 450,000 heat pumps in existing homes each year by 2030 - which will require roughly 38,000 more people to be trained in installing them.

The industry is not growing quickly enough to meet this target. In 2024 there were only 8,800 installers, compared to 140,000 registered gas engineers. But existing gas engineers could upskill and grow their business by transitioning to heat pump installations.

So what is the journey for a gas engineer to begin to start installing heat pumps?

The home heating revolution is underway

The home heating industry is at the start of a massive transformation - low-carbon heating is no longer a pipe dream and is on the way to becoming mainstream. In 2024, 60,000 heat pumps were retrofitted to existing homes and still more installed in new homes. That trajectory is set to increase. The government has put in place funding and support to grow the heat pump installer sector. Research shows that over 9,000 engineers completed heat pump training in 2024.

Same skills - just a different heat source

For existing heating engineers the good news is that the switch from gas to heat pumps isn’t as big as they might think. It uses many of the same skills and tools engineers already use every day - just with a different heat source. With some additional training to support system design and other elements of the installation, engineers can start installing heat pumps.

This explainer outlines the options heating engineers have to retrain and upskill to support millions of homes to switch to clean green heating.

How heat pump installs differ from boiler installs

In essence, the principle of heat pumps and boilers are the same - it’s just plumbing with a different heat source. However, the installation process does differ in some ways which might mean learning new skills. These include:

heat loss calculations to determine the size and design of the heat pump and heating system
MCS paperwork
administration related to grant funding applications, distributor network operator (DNO) connection, consumer protection schemes and similar processes
ordering the bespoke kit
commissioning the system
collaboration with other trades including electricians for power connection or builders for creating the level stand. An apprentice or plumber’s mate may be required at times as heat pumps tend to weigh a lot more than boilers so it is a two-person job to carry and get it into place.

Different jobs may require different mixes of these things, especially depending on whether the engineer uses an umbrella scheme or their own Microgeneration Certification Scheme (MCS) certification. It might also be the case that some engineers already have expertise in such areas, particularly people management and working with trades.

The journey

To work in retrofit - replacing existing gas or oil heating systems with heat pumps - engineers will need to become affiliated with MCS.

MCS is an independent scheme that certifies installers of renewable energy technologies - such as heat pumps. It exists to ensure quality installs and to provide consumer protection.

In retrofit, only households that use MCS-certified installers can access financial support from governments: the £7,500 grant offered by the boiler upgrade scheme in England and Wales, or the £7,500 grant and interest free loan available in Scotland.

This means that most consumers will only buy a heat pump from an installer affiliated with MCS.

There are three routes to becoming MCS affiliated:

1) Join an MCS umbrella scheme

This is the easiest route for sole traders and microbusinesses and can be done very quickly. Their installation will be MCS-certified through the umbrella scheme’s certification.

The umbrella scheme company will provide support with some of the work - for example, heat loss calculations, system design, or commissioning - leaving the engineer to focus on the installation itself.

The scheme company may also provide training and job leads, and they usually take care of most of the paperwork.

However, there is likely to be a fee to the scheme operator or day rate earnings for leads they provide.

1) Join an MCS umbrella scheme

This is the easiest route for sole traders and microbusinesses and can be done very quickly. Their installation will be MCS-certified through the umbrella scheme’s certification.

The umbrella scheme company will provide support with some of the work - for example, heat loss calculations, system design, or commissioning - leaving the engineer to focus on the installation itself.

The scheme company may also provide training and job leads, and they usually take care of most of the paperwork.

However, there is likely to be a fee to the scheme operator or day rate earnings for leads they provide.

2) Join an MCS-certified installer business

As above, it isn’t necessary for every individual to go through the certification process. An engineer could join a large installer company or a smaller business with MCS certification as an employee or subcontractor, or even join a group of sole traders coming together where one member is MCS-certified for heat pump installation.

For existing heating engineers with no experience in heat pumps, their employer will likely provide training and support, and may also cover the cost of some of that training.

Many companies prefer those who have done heat pump training and have some experience working with them.

2) Join an MCS-certified installer business

As above, it isn’t necessary for every individual to go through the certification process. An engineer could join a large installer company or a smaller business with MCS certification as an employee or subcontractor, or even join a group of sole traders coming together where one member is MCS-certified for heat pump installation.

For existing heating engineers with no experience in heat pumps, their employer will likely provide training and support, and may also cover the cost of some of that training.

Many companies prefer those who have done heat pump training and have some experience working with them.

3) Become a fully MCS-certified heat pump installer and designer

This is probably the best route for those who want to focus heavily on heat pumps and set up their own business.

Engineers will need to attend an approved heat pump training course, register with a consumer code, choose a quality management system, fit a heat pump and have this installation inspected by an assessor. MCS will be changing their requirements to reduce complexity, with updates rolling out over 2025-2026. Find out more about the redeveloped installer scheme on the MCS website.

This route offers the engineer complete control over their work from start to finish. It does take longer than the other options and requires some additional administrative work. It also costs around £2,000 to become approved and there will be annual ongoing inspection fees.

MCS has split the accreditation so engineers can become qualified as an installer, designer or both. This gives the option for engineers to link up with others if they only choose to get accredited in one side of the work.

In Scotland, funding is available to become MCS-certified through the MCS Certification Fund, and other local schemes may also be available. More information about the MCS Certification Fund and related schemes is available on the MCS website.

3) Become a fully MCS-certified heat pump installer and designer

This is probably the best route for those who want to focus heavily on heat pumps and set up their own business.

Engineers will need to attend an approved heat pump training course, register with a consumer code, choose a quality management system, fit a heat pump and have this installation inspected by an assessor. MCS will be changing their requirements to reduce complexity, with updates rolling out over 2025-2026. Find out more about the redeveloped installer scheme on the MCS website.

This route offers the engineer complete control over their work from start to finish. It does take longer than the other options and requires some additional administrative work. It also costs around £2,000 to become approved and there will be annual ongoing inspection fees.

MCS has split the accreditation so engineers can become qualified as an installer, designer or both. This gives the option for engineers to link up with others if they only choose to get accredited in one side of the work.

In Scotland, funding is available to become MCS-certified through the MCS Certification Fund, and other local schemes may also be available. More information about the MCS Certification Fund and related schemes is available on the MCS website.

"I'm more confident to tell people about heat pumps now because I actually have more hands on experience."

Ryan Beattie, Start at Home engineer

Install a free heat pump at home

We want to make sure that every installer who trains over the next three years gets an opportunity to install a heat pump at home if they want to. The first installation not only reinforces technical skills but builds confidence, fosters long-term engagement with the technology and enhances credibility with customers.

Start at Home is a funded service set up by Nesta, which gives installers the opportunity and support to fit an air-source heat pump in their own home, giving them practical, hands-on experience.

This is available to engineers across Great Britain - and a number of offers are available from various scheme organisers including umbrella organisations and heat pump manufacturers.

“If you are a good gas heating engineer you will be a good heat pump heating engineer”

Dr Rhiannon de Wreede, scientist and renewables engineer, Warmur

Conclusion

With millions of homes needing upgrading from fossil fuel heating to heat pumps in the coming years, retraining as a heat pump installer could be a wise choice. There are not currently enough fully trained installers out there to meet predicted demand so growing the numbers of installers will be critical.

There has been steady growth in heat pump installations in existing homes and 2024 was a peak year for heat pump installations - with a 55% increase from the year before. Now is the time to be part of the change as there is:

a focus from governments on supporting decarbonising homes
the ongoing £7,500 grant for homeowners to cover some of the costs
a year-on-year growth in owner-occupiers saying they are likely to install a heat pump when they next change their heating system.

As outlined above, there are a number of options available to engineers looking to retrain - from umbrella schemes, to joining an MCS-certified business, to becoming a fully MCS-certified heat pump installer and designer. The Start at Home schemes provide heating engineers with a fully-funded heat pump for their own home as well as expert advice and support with installation.

Anyone considering becoming one of the 38,000 heat pump installers needed by 2030 can look out for training opportunities in their area (funded in England through the Heat Training Grant and in Wales through the Personal Learning Account). To learn more about upgrading their home and learning about the technology, they can visit Start at Home.