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Zero Carbon Heating Trial

Sign up and make change happen

Did you know that the way we heat our homes counts for 15%¹ of the UK’s carbon emissions? Join the pioneering trial aiming to help change this. You’ll even benefit from a free heating system worth up to £15,0002


Register interest


Join the UK's low-carbon heating revolution

Exciting news! We’ve been chosen by the government to run the UK’s largest zero-carbon heating trial. Now, we’re looking for 250 households in the South East to take part in this trial funded by the Department for Business, Energy and Industrial Strategy.

If you join, you’ll have your fossil fuel heating system replaced with a brand new one 
full of low-carbon tech – powered by electricity.

Lighten your carbon footprint with up to £15,000 of tech

Installed in your home for free

By taking part, you’ll not only enjoy a greener home. You’ll help prove that low-carbon heating is cleaner, more cost-effective – and ready for everyone! Lots to feel good about.

You’ll get:

A low-carbon heating system

To replace your current one

Energy efficiency upgrades

Worth up to £5,000 for your home (like loft and wall insulation)

A more planet-friendly home

Your new super-efficient heat pump will cut the carbon caused by your home energy use by 36%³

Full manufacturer’s warranty

Plus 3 years repair and maintenance cover

The coolest way to heat your home

Every home is different. We’ll survey yours to figure out which mix of low carbon tech suits yours best. 
Whatever we end up installing is yours to keep – at no extra cost – once the trial ends. 

Here’s an overview of the clever kit we’re using:

Heat pump

Powered by electricity, they work a bit like a fridge in reverse. They use heat from the outside air or the ground to heat water used in your central heating system and/or hot water. 

They’re super-efficient, too. For each unit of energy used to power them, they create 3 units of heat. And because they work in temperatures as low as -20°C, they can handle even the nippiest UK winter! 

Our trial makes use of several different heat pumps: 

  • Mitsubishi Electric Ecodan Air Source Heat Pumps
  • Kensa Ground Source Heat Pumps
  • Daikin High Temp Heat Pumps

We’ll choose the one that works best with your home. 

Hot water storage

To make sure you’ve got hot water when you need it, we’re using a mix of highly-efficient hot water cylinders and heat batteries – an amazing bit of tech. 

Heat batteries use ‘phase change materials’ to quickly turn stored energy into heat for hot water or heating. And they’re incredibly efficient at storing lots of energy in a small space, too.

Our trial makes use of: 

  • Sunamp thermal batteries
  • Hot water cylinders

Additional home upgrades

We know the comfort of your home is important. Our survey will check if you need upgrades like loft insulation or draught-proofing, then we’ll get your thumbs up to make them. 

We can make up to £5,000-worth of energy-efficiency upgrades to your home, so your heat pump can work at its best. 


Register interest

How the trial works

Step 1

If you're accepted for a place, we'll do a remote home energy assessment to measure the energy performance of your home – and book a date for a home survey

Step 2

Once the home survey is complete, we'll get in touch to discuss the mix of heating tech that will suit your home

Step 3

Once you've given us the thumbs up, we'll book in a date to remove your current heating system and replace it with a new one

Step 4

We'll check the installation has been finished to the highest standard, sign everything off and leave you to enjoy your low carbon home

We’ll be on hand if you have any questions or need help, plus we’ll be in touch 
throughout the trial to get your thoughts on how everything is working. 


Who can take part

Our trial is limited to 250 homes. If you’re interested, you’ll also need to meet the following criteria to be chosen for a place:

  • Be a homeowner in South East England, with outdoor space 
  • Have an internet connection
  • Meet other scheme criteria (covered when we call you)


Register interest

Frequently Asked Questions

It all depends on the fuel you use to heat up your home and hot water. If it’s gas, your gas use will go down and your electricity use will go up. If you have energy-efficiency upgrades installed, it’s likely your overall energy use will go down.

You’ll get the heating system for free, but pay for your gas and electricity use, as usual. If you decide to leave the trial before it ends, you may be charged for the cost of the heating system – the same applies if it gets damaged. If you decide to move to a different type of heating system after we’ve installed this for you, it’ll be at your own cost. 

If you’re successfully accepted onto the trial, we’ll do a survey of your home to check it’s suitable. If it isn’t, but there are changes you can make to address this, then the decision to do so is all yours – and you’d have to cover the cost of this extra work yourself.

We’re working with the UK government to run the trial. It’s fully funded by the Department of Business Energy and Industrial Strategy (BEIS) via the Energy Innovation Programme’s Electrification of Heat Demonstration Project.

Great news – the heating system is yours to keep!

Good news! This heating system is designed to last 20 years – and maintaining it isn’t expensive. OVO/the trial will cover the cost of annual maintenance and any repairs for 3 years from your installation date. After that you’ll need to pay for any annual maintenance checks needed on the system – this should cost about the same as a boiler service.

But more good news! Each component for the system comes with a manufacturer’s warranty which will cover most problems over the warranty period. (Just be sure to check the warranty periods for each component as they might vary). 

You’ll need to read your warranty carefully to understand what’s covered by it and what’s excluded. Plus, anything you need to do to make sure the warranty is valid – like registering it with the manufacturer, or carrying out certain maintenance checks. You’ll be responsible for the cost of any repairs or replacements not covered by the warranty, for example if you damage the system or forget to register your warranty.

We’re looking for it to run for 1.5 years from the date we install your new system. Although we may need to extend the trial beyond this. If so, we’ll write to you beforehand to let you know.

Click here to see which locations we consider as South East England.

We’ll monitor the energy use of your home until 1st April 2022 in order to check the efficiency of the system. And we’ll need to share this info (along with your name and address) with our trial partners: Retrofitworks, Parity Projects, and BEIS and their partners Energy Systems Catapult, DELTA EE, who are managing the trial on their behalf. We will also share your data with our installation partners.

Feedback is key with a trial like this! So, we’ll also ask you to share your thoughts about the new system with consumer survey companies Kantar or ICF, on behalf of the Government. For more info about how your data will be used during the trial please see our Privacy Policy.

Sure – you can call our team on 0330 102 7423  (Mon-Fri, 9am-5pm) or email us at [email protected].

Kaluza is an intelligent grid tech company, part of the OVO Group, leading the digital transformation of the electricity system. Their mission? To connect all devices to a smart zero carbon grid, and help make the global transition from fossil fuels to renewable energy. Find out more here

Kaluza will connect the heating appliances to its smart flexibility platform, streaming and analysing the data from sensors on every device. Insights from Kaluza’s clever technology platform will help give the trial partners an in-depth understanding of how the heating systems are behaving across homes. 

From there, the really exciting part...Kaluza will explore how further cost savings and carbon reduction could be achieved if the devices were coordinated and intelligently controlled to consume energy – when it’s cheapest and greenest for the grid.

Retrofitworks are a cooperative of installation engineers with a range of skill sets and trades. They make things simpler for customers because their retrofit coordinators build the property specification, liaise with the engineers, and coordinate the job to make sure the system performs effectively. Find out more here.

Retrofitworks will survey your home to make sure a heat pump is suitable – and identify any issues that might stop you joining the trial. They’ll then use the survey results to work out what type of heat pump and mix of heating tech is most suitable for your home. Their carefully vetted engineers will then install devices in your home to the highest standards.

Parity Projects use a range of publicly available data to model the energy efficiency of homes. Find out more here.

In this trial, Parity Projects are helping us to identify homes which could be eligible for the trial. They’re also modelling the energy-efficiency of our trialists' homes so we have a good idea of what’s needed, even before the site survey. This saves time and identifies the key questions for the site survey.

Sunamp delivers market-leading thermal energy storage to homes, businesses and communities around the world. Efficiency is what they go for. Find out more here.  

Sunamp’s thermal batteries are market-leading innovations, offering highly-efficient thermal storage within a small space (unlike a large hot water tank!). In this project, Sunamp will be supplying their commercially available UniQ thermal batteries for installation, product warranty and project support.

Originally founded in 1921, the company known as Mitsubishi Electric has almost 100 years of experience in providing reliable, high quality commercial and domestic products to consumers all over the world.

Mitsubishi Electric now leads the UK domestic heat pump market with products such as their multi award winning Ultra Quiet Ecodan. Find out more here.

Combining engineering ingenuity and years of ground source expertise, every heat pump in the Kensa range has been designed and tested to exacting standards for optimum efficiency and ease of use. Find out more here. 

Daikin are devoted to providing high-quality products and total climate solutions to create comfortable and sustainable interior environments for all of the people and regions of the world. Find out more here.

The system is compatible with radiators, but the survey would highlight if any of the existing radiators are too small. We’d upsize radiators as needed & talk you through this after the survey. Our goal is to make sure your radiators can release enough heat into the room to keep things warm, so sometimes bigger radiators are needed.

We'll remove your boiler & hot water tank (if you have one). The heat pump would then need to be installed on an external wall of your house, ideally near connections with your existing heating system on the other side (like pipework to radiators). The external heat pump needs to be plumbed in through the external wall (without major structural changes to the wall, just pipes feeding through). The new hot water storage system (cylinder or heat battery) usually goes where your old tank or boiler was. The existing pipework is usually OK. All of this will be covered in the site survey.

Yes, this is where the Sunamp heat battery comes in. It’s like a hot water tank, but better – using off-peak energy to charge up and delivering heat on demand when you run a tap. The power output is more than enough to generate hot water the same as a combi boiler does, and also at mains water pressure – so the output temperature shouldn’t be a problem. The capacity of the heat battery needed will depend on the size of your home, the number of people living there and bathrooms. This will also be covered during the survey.

This trial is a BETA trial - as the trial develops certain elements and processes are subject to change. To view full trial terms and conditions click here

This figure comes from this report by the Committee on Climate Change and its Adaptation Committee. 

2 Depending on the specific heating system design for your property.

Replacing a gas boiler with a heat pump can reduce home energy carbon emissions by approximately 36%. This is based on the average UK household’s energy use in a year. Emissions factors were sourced from BEIS (the Department for Business, Energy and Industrial Strategy). The coefficient of performance for the heat pump used in this trial was 2.8.

To see BEIS privacy statement for this trial, please see

If you are eligible for this trial we may ask you to participate in research. For more information see

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