Endorsed by Which?

AOS Energy Efficient Heating Systems Limited

4.9

259 Reviews

Opening Hours
Today - 08:00–17:00
  • Monday 08:00–17:00
  • Tuesday 08:00–17:00
  • Wednesday 08:00–17:00
  • Thursday 08:00–17:00
  • Friday 08:00–17:00
  • Saturday - Closed
  • Sunday - Closed

What is a Which? Trusted Traders Hertfordshire Trading Standards Approved Endorsement?

Which? Trusted Traders has partnered with Hertfordshire Trading Standards to create a Hertfordshire Trading Standards Approved endorsement. In addition to our standard trading standards assessment, this trader has had a DBS check and is subject to a Trading Standards intelligence check

About

AOS Heating has been one of the industry's leading experts in the Heating & Boiler industry for over 36 years.
Established in 1984, AOS are family run business who is proud of the reputation we have accomplished over the years.
AOS are a trusted company due to our outstanding customer service record, not only do we provide an honest, reliable service we also offer first class central heating, electrical & plumbing services for all.
Whether you need repairs or servicing to an existing heating system or you are interested in a completely new central heating installation we'll make sure you get the best results.
What's more AOS are also specialists in the most up-to-date heating advancements, including renewable & green technologies such as the latest energy efficient boilers and air source heat pumps. Whatever the job, you can rest assured that you are in expert hands.

What we do

  • Plumbers

    • Emergency plumbing services
    • Unvented cylinder installation and maintenance
  • Boiler, central heating and gas engineers

    • Boiler installation
    • Boiler repair
    • Boiler servicing
    • Radiators and central heating
    • Gas safety testing and inspection
  • Renewable energy

    • Air source heat pumps

Customer reviews

Why you can trust these reviews

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

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

4.9
259 reviews
Customer Service
4.9
Quality
4.9
Value
4.8
Sort by
AOS Plumbing & Heating
Customer Service
Quality
Value
AOS have just replaced our ageing boiler. We've been using AOS for 19 years now and subscribe to their monthly maintenance plan. AOS have always provided a speedy service to the issues we've faced. The engineers who attend the calls out are always friendly, professional and keen to listen to my descriptions of the problem(s). Work is always tidied up and areas left clean.
Customer in Hertfordshire Posted on 27/03/2025 , work completed 17/03/2025
Installation of a new gas boiler
Customer Service
Quality
Value
AOS installed our old boiler, a 'Which? Best Buy' at the time, about 15 years ago and, in the interim, we used their maintenance system to look after it. All without a problem and with quick response when needed. It was an exemplary service. However, the time came when a replacement was needed. It was very easy dealing with the company to arrange the replacement. In the price quoted, they offered, without any request on our part, to instal the current 'Which? Best Buy', a Bosch Worcester Greenstar i System Compact boiler. We found that the price quoted was fair and reasonable and accepted the quote. It was installed today, the necessary scaffolding was installed early and before the AOS's 3 workers arrived on time and work began. We were not disturbed beyond what might be accepted for the job being done. They were quiet and friendly and taught us what we needed to be taught clearly and succinctly. By late afternoon the job was completed. Congratulations to the 3 workers and to the company for a job well done and to our complete satisfaction.
Customer in Essex Posted on 24/03/2025 , work completed 24/03/2025
Replaced Existing Worcester Bosch Boiler after 17 years use
Customer Service
Quality
Value
Very happy with good service and advice replaced with an updated new Worcester Bosch unit and improved condensate drainage for freezing temperatures. Engineers on site were efficient with help and assistance for some remedial work needing attention. Also my annual maintenance call out contract premium reduced due to the new installation for next 2 years. Very happy.
Customer in Hertfordshire Posted on 13/03/2025 , work completed 20/02/2025
Installation of Air Source Pump
Customer Service
Quality
Value
We had an Air Source pump fitted In August 2024. This has exceeded our expectations. It keeps the house at a constant temperature. The AOS team were exceptional from the initial survey to the completion of the project. The staff were courteous and worked extremely hard always updating us on what they were doing. I have no hesitation in recommending them.
Customer in Hertfordshire Posted on 19/02/2025 , work completed 30/08/2024
Great Service
Customer Service
Quality
Value
I have been a customer of AOS Heating for some years, and have always been very happy with their service. We have a maintenance contract with them so this morning I rang for help because the central heating wasn’t working. An engineer arrived within 30 minutes, found the problem, fixed it and left - all within a hour of my phone call! It’s a cold morning so to say I am pleased is an understatement!!
Customer in Hertfordshire Posted on 05/02/2025 , work completed 05/02/2025
Boiler replacement
Customer Service
Quality
Value
AOS priced to remove the existing boiler and associated tanks and pipes and replace with a new boiler The work was over two days and went to schedule and price The engineers were tidy and professional and explained what they were doing as the job went along Handover of the new boiler and working instructions was comprehensive All in all, I was impressed
Customer in Greater London Posted on 26/11/2024 , work completed 22/11/2024
Lightbulb Moment
Customer Service
Quality
Value
The very old light fitting in the dining area was rarely used. It was connected to an equally old dimmer switch. When a family member came to change a bulb recently it went pop and nothing worked. I didn’t know of a reliable electrician so I rang AOS, the company that have been my “go-to” as they fitted my new boiler recently and several other similar jobs. They recommended Luca. I said I didn’t need a dimmer switch and was given a price for the job and a date so when Luca, the electrician from AOS, arrived in a smart uniform and cheerful face I was very relieved. He quickly assessed the situation and replaced the dimmer with a standard on/off switch. Due to arthritis, I have been unable to get on step ladders so the glass shades were looking extremely grubby. Luca very kindly removed the shades and while I was washing them in the kitchen, he wiped the light fitting all over and replaced the three glass shades and put in the bulbs I’d got in readiness. It’s really lovely and bright now and I am so grateful for his kindness and help. Thank you!
Customer in Essex Posted on 13/11/2024 , work completed 11/11/2024
Superb Experience of new Air Source Heat Pump
Customer Service
Quality
Value
Deciding to switch to Air Source Heating was a significant one. Despite the mixed opinions we encountered, our research and understanding led us to believe that it was the right choice for us. We’re delighted with the installation and the system’s performance. From the informative sales pitch to Lee’s helpful survey and installation assistance and the highly skilled work of Ryan, Sam, and Luca (who are perfectionists and passionate about the quality of work they do and are a true asset to your company), the entire process was first-class. The quality of the installation is truly impressive, and the overall customer experience is top-notch. Please extend our heartfelt thanks to all of them.
Customer in Cambridgeshire Posted on 08/11/2024 , work completed 28/10/2024
Great Professional Job
From the village hall meeting where AOS gave background info on heat pumps and exploded some of the myths around them, to the quotation process, survey and then installation they have been superb. A great local company with bags of expertise in retrofitting heat pumps to all types of properties. I have delayed my review to see how the heat pump performed as the weather got colder. All I can say is that so far the house is warmer, the costs vs oil are lower and so we are very happy in taking the plunge to this method of heating and hot water. Check out Octopus Energy for some very innovative heat pump tariffs. Overall the experience has been excellent and I have no hesitation in recommending AOS. First-class job from a local company.
Customer in Cambridgeshire Posted on 06/11/2024 (Reviewer did not use service)
Installation of Air Source Heat Pump
Customer Service
Quality
Value
AOS have an excellent team in all departments of the office and in the engineers who visit to carry out the work installing our Air Source Heat Pump. We were cared for throughout the process, from the initial survey to the completion of the installation and arrangement of the aftercare package to maintain the system. The onsite team were friendly, knowledgeable and hard-working. They took care each day to leave us with hot water for showers and a clean tidy home. AOS installed and maintained our previous gas boiler so efficiently for 15 years that we were 100% confident to ask them to install our new system.
Customer in Central Bedfordshire Posted on 05/11/2024 , work completed 14/10/2024