Endorsed by Which?

Diamond Green Energy Limited

5.0

28 Reviews

Opening Hours
Today - 24 hours
  • Monday - 24 hours
  • Tuesday - 24 hours
  • Wednesday - 24 hours
  • Thursday - 24 hours
  • Friday - 24 hours
  • Saturday - 24 hours
  • Sunday - 24 hours

Why you can trust this trader

After undergoing rigorous assessment to become endorsed, every Which? Trusted Trader agrees to our Code of Conduct. This gives consumers the reassurance that they have the best possible protection and adds an extra layer of security to ensure best practices and procedures are followed. Which? fully investigates any breaches and will take any necessary action to ensure consumer protection.

About

Established in 2005, Diamond Gas & Heating are proud to be Worcester Bosch accredited installer’s since 2008 and recently approached by WHICH to become a “WHICH Trusted Trader”.

Diamond Gas and Heating have the knowledge and expertise needed to ensure that you receive nothing but the best service. Our reputation has been developed through hard work and reliability which is why we are the area’s number one choice for heating & gas related work.

We are based in Portsmouth, Hampshire and operate over a radius of around 50 miles from here.

Whether you are a private customer looking for a personal service or a Landlord or looking for someone to look after your complete heating needs then Diamond Gas & Heating Ltd can deliver what you need.

What we do

  • Boiler, central heating and gas engineers

    • Boiler installation
    • Boiler repair
    • Boiler servicing
    • Gas safety testing and inspection
    • Radiators and central heating
    • Power flushing
    • Underfloor heating
    • Immersion Heaters
    • Gas fire repair and servicing
    • Gas cooker repair
    • Gas cooker installation
  • Heating contractors

    • Central heating systems (installation and servicing)
    • Immersion Heaters
    • Oil fired heating equipment
  • Plumbers

    • Emergency plumbing services
    • Unvented cylinder installation and maintenance
    • Water softener installation and maintenance
  • Air conditioning contractors

  • Renewable energy

    • Air source heat pumps
    • Ground source heat pumps
    • Home energy analysis

Customer reviews

Why you can trust these reviews

All reviews are verified as being genuine and a true customer of this trader.

How can we be so sure?

100% of the reviews we publish have been through our stringent moderation process.

5.0
28 reviews
Customer Service
5.0
Quality
5.0
Value
5.0
Sort by
Boiler Installation
Customer Service
Quality
Value
It was very easy to to arrange a boiler replacement with Diamond Green Energy, and the software supporting the selection/fitting and payment processes all easy to use. The fitter Jay, made a good job of replacing a Combi Boiler in a day, he worked cheerfully and was happy to explain what he was doing and how the boiler worked. He cleaned up after the fitting process, taking away all the arisings. He was obviously experienced in fitting the Worchester Bosch boiler, the replacement chosen as it has a "Which" recommend (he does fit other makes of boilers). Brian.
Customer in Posted on 11/02/2025 , work completed 10/02/2025
New Small Air Conditioning Unit, very helpful, excellent communication and tidy, speedy installation
Having just had a new air conditioning unit fitted in my garden room by Diamond Green Energy Ltd I feel compelled to write a very positive review. From the initial moment of contact, I felt confident. Speedy communication, and responsive service from the office. A really professional service all around, whilst at the same time feeling as though they were like friends! The two fitters were especially nice, prompt, polite and efficient - nothing too much of an issue. Would highly recommend - well done Diamond Green. I am already considering another unit in the house!
Customer in Bournemouth, Christchurch and Poole Posted on 14/11/2024 (Reviewer did not use service)
Replacement of ancient LPG boiler and hot water cylinder with a leaking coil.
Customer Service
Quality
Value
I felt comfortable with this company from start to finish. Telephone and e-mail contact has always been friendly and professional. My cottage is individual and characterful, presenting challenges to the team. Steve who did the initial survey seemed to enjoy trying to solve the problems, and came up with ideas that would work. Kev who was joined by Drew also found ways of carrying out the work so it would be as unobtrusive and efficient as possible. They all treated me, my cottage and my nervous dog with respect, tried hard to cause as little disruption and mess as possible, and cleared up after themselves. I was involved in any decisions that needed to be made. At no stage was I encouraged to have extra work done that would be costly and unnecessary. It is wonderful to have a warm cottage and hot water again, thank you. I would use the company again, and have no hesitation in recommending it..
Customer in Hampshire Posted on 13/07/2023 , work completed 20/04/2023
Brilliant Service
Customer Service
Quality
Value
My mum's boiler broke down and she had no heating or hot water. Luckily it was boiling hot so we didn't need the heating and had an electric shower. However Mum is 87 years old, so she was still very stressed about it. We tried to find a company online and after dealing with a number of what I would describe as salespeople, it was refreshing to talk to Diamond. They did a video call the same day and checked more on the video call than some plumbers who actually came to the house. We instructed Diamond and choose a Worcester boiler. The boiler was fitted last week and the lad that came was great, he put mum completely at ease. He finished on time and left no mess whatsoever. I'll be recommending Diamond to anyone that will listen. Special thanks to Joe the installer, Dwayne in the office and Ian who did our quote.
Danielle in Surrey Posted on 16/06/2021 , work completed 11/06/2021
The trader replied (on 17/06/2021)
Thank you very much for you kind review. I am so pleased we were able to put your mum's mind at rest. Thank you for choosing Diamond Gas and Heating to install your boiler.
very Impressive Job
Customer Service
Quality
Value
The young tradesman - Alfie Daniel - was a very hardworking and professional young man. He worked on his own, he was methodical and he cleaned up after his days work. The removing of two boilers and fitting of a new Worcester Bosch boiler plus removing and fitting pipes was carried out in two days. We would recommend Alfie and Diamond Gas without hesitation.
Brian, Hampshire Posted on 25/09/2017 , work completed 25/09/2017
Excellent from beginning to end
Customer Service
Quality
Value
From the initial phone call, to the survey visit, to the three days required to start and complete the work, I have been given politeness, help, courtesy, excellent advice, and ending with very professional and clean installation work. I am very pleased with them and would highly recommend them.
David, Surrey Posted on 04/09/2017 , work completed 04/09/2017
Friendly, efficient, knowledgeable, informative.
Customer Service
Quality
Value
Boiler Service Plus, fixed two leaks in central heating. Very informative and professional.
C, Hampshire Posted on 25/04/2017 , work completed 25/04/2017
Very good job
Customer Service
Quality
Value
Very courteous, efficient & professional. Very good job done.
Lorraine, West Sussex Posted on 30/03/2017 , work completed 30/03/2017
My review
Customer Service
Quality
Value
Extremely good job
Peter, Hampshire Posted on 24/03/2017 , work completed 24/03/2017
First class installation
Customer Service
Quality
Value
From start to finish Diamond stood out. The initial quote was thorough, Ian listened to our requirements and then checked to make sure our selection of boiler was suitable. Come the day of the install Brad and Lewis were on time, polite and took the trouble to explain what was happening. The couple of small issues found were dealt with explaining our options, nothing was too much trouble and they cleaned as they worked. When it came to commissioning the boiler there were issues with the house supply, they contacted Southern Gas Networks and arranged for an engineer to visit. Throughout the gas supply problems Diamond helped us to ensure the Gas supplier fixed the problem and Ian visited on multiple occasions to ensure the problems were properly resolved. It is not until there are problems that you find out how good your installer is and all I can say is top marks we could not have asked for a better service. I would thoroughly and whole heartedly recommend using Diamond, everything about them was spot on. They went above and beyond what was to be expected, thanks to all the team top job top service.
Robert Posted on 03/03/2017 , work completed 03/03/2017