Your Intelligent

Energy Solution

We are Cinergi, an experienced team of heating and power engineers specialising in renewable energy installations including air source heat pumps, solar panels, under floor heating and heat recovery. We are based in Southampton, serving homes and businesses throughout Hampshire and the South Coast.



We are a team of highly accredited engineers who design, install and service both mechanical and electric power systems. We have been in the business for 40 years, forging a reputation as trusted domestic boiler experts. This is very much still a part of our offering, but power has evolved and so have we.

Our services have expanded in recent years to offer more modern and sustainable sources of power such as air source heat pumps, solar panels and electric vehicle charging stations. We are passionate about sharing our extensive knowledge with our customers, and so we offer impartial advice to help each one achieve the most efficient and cost-effective power solutions for their home or business.

why choose


We are a close-knit, friendly team of engineers, with generations of combined experience spanning 40 years. We have a reputation for excellent service and quality workmanship, which is a source of great pride. Our commitment and high standards are evident in our industry accreditations and our customer reviews.

We care deeply about what we do and have our customers’ best interests at heart, so your home or business could not be in better hands.

We specialise in both gas and electric solutions

Cinergi is unique in that we can provide both gas and electric energy solutions. So if you are looking to have your traditional gas boiler serviced or replaced, or maybe considering a move to an electrical source of power to heat your property, then we can present you with all available options.

As an independent company we have no incentive to push any particular systems or products. You can trust us to give you honest advice as to the most efficient and cost-effective options available to your particular project.

professional installers

Accredited Installers

Experienced Technicians

cinergi reviews

Trusted To Deliver

customer support and advice

Impartial Advice

want to chat about energy solutions?

get in touch

We’d love to talk to you about your energy requirements for your home or business. You can get in touch by calling 0800 321 3142. Alternatively, click the button below to arrange a callback from one of our team at a time that suits you.

Cinergi News and Insights

As a trusted supplier of cutting-edge heating solutions, we are excited to share valuable insights and information to help you make informed decisions about your heating needs. Whether you’re a homeowner looking to upgrade your heating system or a business owner interested in sustainable energy solutions, our blog is here to provide you with expert guidance and inspiration.
Air source heat pumps working with solar panels

How do air source heat pumps work with solar panels?

As the UK continues to embrace sustainable energy solutions, combining the power of air source heat pumps (ASHPs) and solar panels is a compelling option ...
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Are heat pumps mandatory on new builds?

Are heat pumps mandatory on new builds?

January 2024 You may have seen the headlines about gas boilers being banned from 2025. So what does that mean for existing and new build ...
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air source heat pumps disguised

How can I make my air source heat pump look better?

While the benefits of an air source heat pump are evident to many homeowners, at Cinergi, we often hear reservations about their appearance. Granted, an external heat ...
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Highly rated

Cinergi Reviews

Cinergi - Renewable Energy SolutionsExcellentCinergi - Renewable Energy Solutions5.0 Based on 58 reviews fromSee all reviews review us onEvan D. ★★★★★ Great install from local firm. Friendly installers. Good answers to questions. Sensible advice. Helpful handover of equipment and follow up from officePhilip L. ★★★★★ I selected Cinergi from 3 possible suppliers who had submitted a quotation for the supply and installation of a heat pump and battery system. Before taking the final decision to invest the company already impressed me with their responsiveness and ease of engagement. The team took the time to answer all my questions even if that meant ploughing through a long email. A lot of thought went into selection of the right ASHP which included picking the vendor, not just the size of the pump. We are pleased with the Vaillant user interface. I’m looking forward though to being able to download more operational data to help me understand and optimise the running of the system.The installation team was led by a very competent and personable plumber. He kept us well informed about progress and the challenges he had to address along the way. He was very approachable and exuded knowledge so never felt out on a limb regarding the installation. The components for the ASHP system have been neatly spaced out in the attic and outside and work ethics were good: attention to safety and tidiness all along.A few weeks into running the new system we flagged that the biggest radiator took too long to heat up. Cinergi arranged for the plumber to come back within a couple of days and he addressed the problem by rebalancing the radiator system and tweak the setting of the circulation pump. We took the opportunity to learn from him about other operational matters.I greatly recommend the company for your heat pump project.Andrew L. ★★★★★ I’m building a new house and need a heat pump, solar and battery. Cinergi are the only Company where the person you speak to (Meghan) organises a Director to call back when there’s a highly technical query. Ian certainly knows his stuff and it’s easy to see why they have so many 5* Reviews.David D. ★★★★★ Cinergi were recommended by my Vaillant Heat Pump supplier. They offer an annual service plan, and responded helpfully and professionally to a recent problem. Easy to communicate with too. I can highly recommend this Company.Hugh C. ★★★★★ Excellent heat pump and underfloor heating installation from start to finish. Easy heat loss assessment and quoting process. Clear, friendly and prompt communication from the office staff. Conscientious installation team. The system is working as it should and meeting expectations on COP. Good liaison with the subcontractor doing the underfloor heating. One slight problem when the hot water tank didn’t fit the space but this was apologised for and rectified. Price was in line with other quotes. Highly recommended!Stephen T. ★★★★★ Just had a Heatrae Sadie and a Sunamp Thermino fitted by Cynergy Ltd Romsey. The installation was carried out by Adam (heating engineer) Dan and Josh (electricians). They were all very professional and nothing was too much effort.All in all from first discussion with Ian to the end of installation has been an excellent experience.Steve,The Malthouse, RomseyPaul W. ★★★★★ We had Dan come and inspect our property in order to give us a quote for a new air source heat pump. Waited a week and no quote so contacted Cinergy. 2 weeks later still no quote. Finally got quote when I left a poor review.Response from the ownerHi Paul, we hope you and the family are well 🙂 I've taken a look into what happened here and can confirm that the quote was sent to your e-mail address 2 weeks prior to you leaving the above review (1 week after surveying your property). Although we do aim to get our proposals quicker than this, some of the team were on annual leave this week, for which I do apologise. When we got notification of your review, 2 weeks later, we resent your proposal to both e-mail addresses we have on our system for yourself, and called to ensure you received them.I can only assume that your original proposal found its way into your junk founder, and I do apologise for any inconvenience caused.As always, please do get in touch if we can help you in any way :)The Cinergi Team Nicola B. ★★★★★ Cinergi are amazing, incredibly respectful and very tidy plus the aftercare is second to none. I would highly recommend!Jade S. ★★★★★ Cinergi are a professional family run business. They were able to answer allquestions we had with the Tesla battery installation. The installation was completed as required and it was ensured that the work was completed to a high standard and left in a tidy state. Would highly recommend.Juliet W. ★★★★★ Cinergi have been fantastic with our job from start to finish. All of their employees (we met 6 in total) were polite, helpful, tidy and a pleasure to have around both inside and outside of our home. They answered our daft queries without difficulty, made helpful suggestions and ensured we understood the system they had installed. I wouldn’t hesitate to recommend them.Chris Z. ★★★★★ Thanks to everyone at Cinergi on a great job - we couldn't be happier with the solar generation system and the staff were helpful, transparent, friendly and knowledgeable at all stages. We'd happily recommend Cinergi to friends and will be in touch in the future to install an Air Source Heat Pumpangorfarax65 ★★★★★ It is the second time I have used Cinergi once for an air source heat pump and recently for solar panels and a battery installation. I have been very pleased on both occasions with the standard of work proffesionlism and after care that the company give, I would not hesitate to reccommend them.Jonathan P. ★★★★★ I was initially hesitant to know where to go when upgrading to a Heat pump in a large Edwardian detached house. I had no need to be concerned.Cinergi guided me few the few hurdles from start to finish. They also handled the Heat pump grant for me.The system was installed in the Autumn of 2022 and the bills plummeted, assisted by solar panels and having batteries.i can't thank them enough and have been very happy and more importantly toasty warm with the Vaillant system.Jonathan Perry (Bournemouth)Peter S. ★★★★★ Overall a positive experience. The system has been up and running now for around 6 months and had no issues keeping the house warm in the winter. I found the Cinergi team to be always friendly and helpful. When small issues did arise during the installation process and thereafter they were always responsive and helpful in dealing with them. Would recommend.David B. ★★★★★ Delighted with the team’s expertise and knowledge fitting our Daikin heat pump in December 2021. Works very effectively and suited our space and existing pipework very well. Excellent service and follow up maintenance too.Paul E. ★★★★★ Cinergi installed a new ASHP, and did so professionally, with excellent communications and were a pleasure to work with - I would recommend them and would use them again.Abby B. ★★★★★ Professional service and great aftercare, we had an issue with our unit ( not Cinergi’s fault) and they can out and resolved promptly which was great. Very knowledgable about the system and made helpful suggestions to get it working as required with other elements outside of their control.Mark F. ★★★★★ A professional company who were friendly and supportive from the first enquiry until completion of the installation. They offered good advice and were very adaptable in working with me on our install design and timescales as we were doing a renovation at the same time. I have no hesitation in recommending them.david R. ★★★★★ Cinergy are the first company that I have ever felt safe to recommend to friends. Their installation of a high temperature air source heat pump system, replacing our smelly old oil boiler was brilliant.Daniel G. ★★★★★ I had a heat pump, battery and solar panels installed through Cinergi and would 100% recommend. High quality, professional work and great, friendly customer support.This scale is installation into an older property was never going to be without complication but they were brilliant throughout, going the extra mile to bring it all together.Andy P. ★★★★★ In April 2022 Cinergi fitted an ASHP to our house and removed the gas boiler. I reviewed this on Trustpilot in May 2022 but forgot to do the same here. Below is my Trustpilot review, followed by a few comments made one year later.************************Installation of ASHP in place of gas boilerEarlier this year my wife and I contacted Cinergi with various questions concerning the viability of replacing our gas boiler with an ASHP. The outcome was that in April they installed a Vaillant Split air source heat pump, which seems to be exactly what we were looking for. Overall, we're very pleased indeed with the whole process - from the initial discussions, survey and installation, through to arranging for all relevant certificates, guarantees etc to be sent to us.The Cinergi team listened carefully to us, addressed our concerns, advised us on the placement of the outside unit and took great care in fitting the inside unit, tanks, pipes etc into our small utility room – a work of art!When required, the thing enthusiastically heats up our water tank and no doubt won't make any fuss about keeping our house warm through the winter months.Happy days!*******************************It's now June 2023. Our ASHP has supplied us with hot water and heating for just over 12 months, including unusually cold winter weather, without any fuss or bother at all. It's lived up to our hopes and expectations. The weather over any two years is never exactly the same, but during the 12 months after the ASHP's installation the energy supplied to our house (all electricity) was exactly 40% of that supplied (both gas and electricity) during the 12 months before its installation – ie our energy intake has fallen by 60%.We're now back in touch with Cinergi in order to add some more PV cells.paul H. ★★★★★ Did the job very well and exactly as scheduled, expertly with no inconvenience. Would recommend this company as opposed to the other companies I contacted to do the installation. Support since installation has been good. The system has worked well.Ayjay E. ★★★★★ Cinergi were a joy all the way from quote through installation of the heat pump and on to annual servicing. They have been prompt and efficient throughout and nothing is too much trouble.Other companies who quoted did not take enough time or care to consider what needs or requirements this particular house had and so their recommended solutions did not take into account levels of insulation, use and occupation of the house or even practicalities. Cinergi took the time to explore the house properly and were even willing to come up with solutions to upgrade the radiators without having to move the giant sofa! a really good service and I am delighted with my heat pump. It is the perfect solution for rural homes who are not on the gas grid and Cinergi are the perfect team to do the job!Patrick ★★★★★ I would highly recommend Cinergi if you’re considering purchasing an ASHP.I carried out lots of research on the web to try to find the best equipment to use and how it would all work in our home, I found it quite complicated especially trying to figure out the size of equipment required.I contacted several companies for an initial consultation and quote. Dan from Cinergi visited my property and carried out a full assessment of what was required to heat our house and supply hot water. His knowledge was superb, he explained what would be required and how the whole system would work, he answered all my questions including many concerns I had about changing form a traditional Combi boiler to ASHP.I went ahead with Cinergi to install our ASHP system. Ian lead the install team his knowledge was phenomenal, he recommended a few small adjustments which fully optimized the system.All the equipment and materials used on the project were of high quality, the installers were clean tidy and very respectfully. We were extremely happy with the end result and the functionality of the system; our electricity bills have dramatically reduced since installing the system.I dealt with the main office to organise the installation of the ASHP and get all certifications.Kate & Daisy have been extremely helpfully, they really go out of their way to make sure to make sure the customer is happy.Overall a great company, extremely knowledgably with a highly skilled installation team and great customer servicedavid W. ★★★★★ My boiler required replacement and I was considering replacing it with an ASHP. I did not know anyone with one of these so researched the net and approached various companies for advice and cost. I chose Cinergi as they provided excellent advice regarding using some of my existing system and offered components with good on-line reviews. Dealing with them was easy, they were responsive and flexible and commenced the installation earlier than we initially agreed. Their installers were polite, clean, tidy, professional, knowledgeable and very nice to chat with. Don't worry about the noise of an ASHP, I could not tell the heat pump was operating over the noise of a hoover a street away! The water pump remains the noisiest part of the system.Now 6 months on I am through the system's first winter. My electricity bills have been were much less than I have seen on the news. In really cold weather, occasionally I needed to use the gas fire in the living room, but the house was generally a comfortable temperature. The system still seems to be operating as it should and now we have moved into summer the heat exchanger makes a useful side table on the patio! Very happy that the company seems to contact customers on a regular basis.andy F. ★★★★★ Highly recommend Cinergi for all things renewable. They installed a heat pump with solar to our new build and were a pleasure to deal with. Always contactable and accommodating to timescale demands when building our property. Don't look anywhere else !Tom L. ★★★★★ Cinergi replaced our gas central heating with an ASHP in Feb 2022. The process from the assessment to the comissioning was exceptionality smooth.We've been living with the system for over a year and had zero issues with it.We're on their yearly service plan which is also excellent. The team are great, providing an excellent overall service.Chris R. ★★★★★ All staff are very polite and helpful. Heat pump works fairly well. It will be due a service soon and will give an opportunity to make a few adjustments. One major problem is the Heatmiser Control.It allows temperature to drop at least one degree below setting before starting again. From work at university I know this is very inefficient. For heat pumps to compete with Gas boilers they must match the simple technology of a dial to set temperature and the simple advance button to instantly switch on heating.FP U. ★★★★★ Project 1, Installation of Air Source Heat Pump & Removal of old gas boilerProject 2, Installation of Solar PV System: -The company is a very well run and organised family business, demonstrated by the ethos emanating from all.From first Web site impression (Everything, well explained), Enquiry, Survey, Tender, Clarifications, Contract, Installation, Commissioning ….. to Handover Documentation, the Team performed exceedingly well and beyond client expectation.For a time, Solar PV project ran in parallel at the same site location as ASHP installation.Onsite personal, always worked well as a team, helping each other in their areas when required (no demarcation issues, no subcontractors, just one company).Communication with the client was always respectful and courteous, taking time to explain any answers to questions that were put their way. Installation wasn’t rushed but well thought through and agreed with client, must give a special thank you to Justin Parry, whom performed exceptionally well throughout the ASHP project.Water is hot and plenty of it too, central heating system is working well and of course will be tested fully this coming winter 😊Good liaison was had with client for Solar PV install, including the battery of which needed further consideration with respect to installation location and its service access panel.Solar Edge, delayed final live commissioning, due to a software update preventing client app monitoring of the system. Cinergi Ltd worked hard to resolve SolarEdge’s problem and kept client informed and updated.Glad to say, the Solar PV system is working very well and can be monitored on the Solar Edge app.Thank you !!!Cinergi Ltdfor Outperforming 😊Nick W. ★★★★★ Very pleased with the ASHP installation. All the team have been very helpful. A problem was rectified quickly after the install. Handover could have been better as the instructions for Daikin units are unintelligible.Raymond W. ★★★★★ Excellent. Got about four quotes, all different. Some were excessive, things we didn't need. Some were just expensive. Cinergi came and worked out exactly what we needed, gave us the option of a combi or system boiler or heat pump. At that time chose the system boiler. Never had any problems. Shower and water pressure is fantastic. Very efficient and tidy installation, very professional and personal.Mike M. ★★★★★ The installation actually took more than twice as long as most similar installations might take due to unavailability of certain parts. Once parts did arrive, the team were very good at doing the work, they were helpful, adaptable, willing and polite and had to work very hard to achieve the required results (I am not easily pleased and can be a hard taskmaster!) The team were not afraid of hard work and during the installation had to try three techniques before managing to get a very heavy piece of the system upstairs to the airing cupboard. They are a good team and are about to extend my solar PV battery system for me.Adam C. ★★★★★ A great all round experience with the installation smooth and professional. Previously the house was installed with an oil boiler so moving to an air source pump was a nobrainer. If I was to move house again working with Cinergi would also be a nobrainer! Thank you Cinergi for the top 5* job!Steve R. ★★★★★ Everyone at Cinergi was extremely helpful and professional throughout the process in respect to the installation of our ASHP. From quotation through to full design and installation. I can thoroughly recommend them to anyone wishing to investigate the merits of an ASHP over the more conventional heating systems.Hugh G. ★★★★★ We were given good advice on replacement of a gas combi boiler to remove gas usage from our property. They installed a boiler for heating and a heat battery for hot water. Thought was given to the units placement and any problems were quickly and efficiently fixed. Highly recommended.Mark R. ★★★★★ We had an ASP system installed. Great advice and support on what was a complicated decision. System works well and the Team were excellent. Advice and guidance on grant was very helpful. A lovely family companyRob G. ★★★★★ Had an AHP fitted at home and the service was first class. The guys even changed a few parts nothing to do with them while there.System running really well and now its getting hotter the costs a dropping fast.I strongly recommend using Cinergi.Rob GraySimon H. ★★★★★ Rosie K. ★★★★★ I had the pleasure of having Cinergi for the installation and upgrade of my heating system, and I cannot recommend them enough. From beginning to end, they displayed a high level of professionalism, expertise, and customer service that exceeded all of my expectations. Their team was prompt, efficient, and respectful of my time and space, and they made sure to explain every step of the process along the way. The finished product was top-notch, and my home has never been more comfortable. I am so grateful to this company for their exceptional work and would gladly have work on other projects again in the future. Thank you for everything!Steve B. ★★★★★ I had a full Air Source Heat Pump and which heats my home and provides hot water. Cinergi’s install team were polite, courteous and worked without making any mess and completed their work without any inconvenience. My current energy bills are a small fraction of what they used to be and backup and aftercare has been top notch. I would highly recommend Cinergi to anyone considering a high tech, clean, efficient way to heat your property.Matthew A. ★★★★★ Had a car charger (zappi) installed and linked upto my solar panels. Excellence service, friendly and knowledgable staff with quick responses to queries. ThanksIsmail A. ★★★★★ The team at Cinergi were absolutely fantastic. From start to finish, they were open and honest about what we needed for an Air Source Heat Pump system. Despite the cost it was well worth it from the customer service alone. I am definitely looking forward to working with them again.Heather S. ★★★★★ We had our air source system installed just over a year ago by Cinergi so now understand the running costs over a 12 month period. The installation was carried out speedily and with careful considerstion of each rooms needs for heat in the winter. The after sales service has been very good and any issues have been resolved quickly.We only have 1 bill now and that is electric. Overall we are delighted with the system. Never a shortage of hot water all year and although the electric consumption for central heating is high when the external temperature drops exceptionally low over the entire year we believe we saved money.Highly recommend Cinergi & their after sales service.Heather & Gordon Smith Portesham.John B. ★★★★★ From initial contact through to survey, options, recommendations and installation, Cinergi have been excellent. Great knowledge and support choosing an air sourced heat pump, installed to a really high standard. Very professional team. Extremely impressed.Bryan D. ★★★★★ EXCELLENT EFFICIENT AND PROFESSIONAL INSTALLATION OF NEW SYSTEM AND REMOVAL OF OLDAnt L. ★★★★★ Cinergi are an excellent family run business. They competed a complex air-source heat pump installation and the system runs smoothly and efficiently. If I have any issues they are always responsive in coming back to me. I would throughly recommend them.CatrionaMJ ★★★★★ Cinergi installed in-roof solar panels, 10kW battery, ASHP, hot water cylinder and secondary hot water circuit. The system is all working perfectly and we are thrilled with the outcome.Kerstin W. ★★★★★ Excellent service from initial site visit through to commissioning of our air source heat pump system. We were kept fully informed of the process throughout. Polite and friendly plumber and electrician arrived as expected and were helpful and patient with our questions.I would use Cinergi again and will recommend them to friends and family.Max I. ★★★★★ We had an ageing Air Source Heat Pump that we had inherited when we bought the house. It was not operating optimally and was consuming a lot of electricity. We contacted Cinergi to ask for advice and after running through the options we elected to install a new ASHP system. This unit is simpler, quieter and much cheaper to run. The quote for the installation was highly competitive. Throughout the process Cinergi were incredibly helpful - they responded promptly to all emails, answered all our questions and offered practical and informed advice. The installers were very polite, helpful and tidy - the unit was installed with the minimum of fuss - even providing electric fan heaters for the periods when we had no operating central heating. I have no hesitation in recommending Cinergi - and indeed have already done so to a local friend.js_loader