Endorsed by Which?

AOS Energy Efficient Heating Systems Limited

4.9

236 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
236 reviews
Customer Service
4.9
Quality
4.9
Value
4.8
Sort by
Fully lived up to our expectations
Customer Service
Quality
Value
We were introduced to AOS Energy Efficient Heating Systems Limited by a previous satisfied customer of theirs. We needed to replace an oil-fired CH boiler which was over 40 years old and the idea of going fully electric was very attractive, especially with the Government's green incentives and the fact that with a heat pump you get out more than you put in. We made enquiries of several friends and neighbours who had used AOS to make similar conversions, and they were all enthusiastic. "Very clean and tidy", "extremely good plumbers" were typical comments. We found AOS's approach to be very open and honest about issues and possible problems; above all, they are specialists in this field and we felt confident that they knew what they were doing. The date for the start of the installation arrived, and AOS were there on time, began work with no delays and completed on schedule. So the comments we had received turned out to be no exaggeration. Since the system was commissioned we have had no problems and the house has been warm and comfortable despite recent cold weather, including hailstorms!
Tony and Annie in Cambridgeshire Posted on 14/04/2021 , work completed 01/04/2021
The trader replied (on 15/04/2021)
Hi Mr & Mrs Coe, Thank you for your kind words. We are so pleased that you are very happy with your new heat pump system and the service you received throughout the process. We will be sure to pass on kind comments to the whole team. Kind Regards The AOS Heating Team.
Replacement of oil fired boiler heating system with an air source heat pump
Customer Service
Quality
Value
AOS Heating replaced our oil fired boiler with an air source heat pump. They also replaced the hot water tank and all the radiators. Prior to installation we were debating our choice of radiators and AOS Heating helped our decision making process by answering many questions we had and providing feedback on potential alternatives. The AOS Heating team that undertook the installation were punctual, courteous and completed the work when they said they would. As the work was undertaken during pandemic restrictions, the team were careful to adhere to social distancing and were very respectful of an elderly relative in the house and worked around him with minimal impact. Each day the installation team answered our questions patiently and did a clear handover when the installation was completed.
Craig in Central Bedfordshire Posted on 11/04/2021 , work completed 01/04/2021
The trader replied (on 15/04/2021)
Hi Mr Scott, Thank you very much for your review it is really appreciated. We are glad that you are pleased with your final radiators choices and were more than happy to assist throughout the decision making progress. We are also very happy to hear that the installation team were attentive to your needs during the install. We will be sure to pass your lovely comments onto the whole team. Kind Regards The AOS Heating Team.
Works completed as promised
Customer Service
Quality
Value
We are very pleased with the efficient manner in which the whole operation was conducted, particularly with Ryan and his team and their professionalism and work ethic. They couldn't have been more helpful with everything including clearing up on a daily basis. The office team, Charlotte & Sian, were equally on the ball and were able to provide us with answers to all of the questions we raised. We have no hesitation in recommending the AOS team.
Jane & Martin in Buckinghamshire Posted on 10/04/2021 , work completed 08/04/2021
The trader replied (on 15/04/2021)
Hello Mr & Mrs Kempt, Thank you very much for your kind words. It is always so lovely to be able to pass on such positive feedback to our installation engineers and office teams and they really do appreciate it. Kind Regards The AOS Heating Team.
Excellent Professional Service
Customer Service
Quality
Value
Sam and his team installed a large air source heat pump, installed 18 radiators, converted two water cylinders into one all whilst working round an oil fired boiler that had to be retained for other purposes. They were on site when they said they would be and always tidied up at the end of the day before leaving. There were many unforeseen challenges along the way which were overcome without quibble or additional cost. At the end of every day, we were updated with progress and goals for the following day. In addition, we were given plenty of advanced warning for when we were going to be without electricity, hot water and heating which was a godsend whilst three of us were working from home. Sam and his team were polite, courteous, professional and often went above and beyond the scope of the project. In summary, from the initial meeting with Andy on the Sales team through communication with Charlotte and Sian for co-ordination of the project and site survey by Lee, the whole experience with AOS has been a pleasure and we would have no hesitation in recommending them.
Customer in Cambridgeshire Posted on 06/04/2021 , work completed 27/03/2021
The trader replied (on 15/04/2021)
Hi Mr & Mrs Scott, Thank you very much for your review it is really appreciated. We are very glad to hear how happy you are with the service you received throughout the whole heat pump installation progress. Your installation was very large and required a lot of precise planning so we appreciate you noticed the effort made. It was a pleasure to work with you both throughout and we are extremely happy you are so pleased with everything. Kind Regards, The AOS Heating Team.
Best install of a new boiler system I could hope for!
Customer Service
Quality
Value
The AOS team arrived promptly each day and were very conscientious right from the start. All of their colleagues wore masks, put down sheets, and made sure to leave the house as clean and tidy as you could hope for. The works carried out were delivered to a high standard, and they even improved a number of additional items at our property at no extra cost (sorting out some creaking floorboards and a free washing machine install). Their rates are very competitive, and I am so happy we went with them over British Gas. Most importantly, they were friendly and approachable and I felt at ease with their team in our house.
Customer in Hertfordshire Posted on 31/03/2021 , work completed 12/02/2021
Very professional organisation
Customer Service
Quality
Value
AOS Energy Efficient Heating Systems Ltd recently installed an air source heat pump and replaced the hot water cylinder and most of the radiators in my home. Everything was completed according to the schedule. Staff in the sales and service departments were helpful and knowledgeable and communication was clear and easy. The installation team were pleasant, polite and obliging. They made an extra effort to meet the particular requirements of this job. There were a couple of issues with radiators but these were resolved satisfactorily. Everyone has been utterly professional and I'm very happy with the result. I would definitely recommend this company.
Sue in Buckinghamshire Posted on 16/03/2021 , work completed 12/03/2021
The trader replied (on 18/03/2021)
Hi Sue, Thank you very much for your kind works. It was a pleasure working with you on your renovation project. We hope you enjoying your new heating system. Kind Regards The AOS Team.
Service call
Customer Service
Quality
Value
My air source heating did not reach the require temp. booked a service. The previous service was only 6 months ago the office told me that I should have the mobile thermostat in the warmest room. Rubbish. cost of service £150 +vat...I was only asking the system to reach 20 degrees it never makes it. The engineer was helpful and obliging and suggested that the anti freeze/inhibitor be topped up. Phoned the office to pay extra for it. Shock horror they want to charge £250 + vat just to top up. This was on top of the service charge. I have insulated walls and attic with double glazing. How disappointed I am with the system. When it was installed the service was excellent and I had no complaints. Whilst this has been a cold winter to have a system that only reaches 14/15 degree is not good enough.
Customer in Essex Posted on 04/03/2021 , work completed 04/03/2021
The trader replied (on 15/03/2021)
When your heat pump was installed you were advised to upgrade radiators in your home but you chose not to proceed. It was made clear that we cannot guarantee room design temperatures if our recommendations are not followed. You were given 3 x free services which were carried out over the years, the 3rd service was completed 24/06/20 but we advised that the anti–freeze was low & should be topped up. We provided quoted but you chose not to proceed. On 25/02/21 you reported the system not reaching temperature & our service manager explained that you need to keep your thermostat in a room which is designed to react 21c if your thermostat is left in a room designed to 18c then the system won’t reach temp. You did not wish to take this advice & asked for a service instead. As all your FOC services had been used we explained that this visit would be chargeable. We suggested that you wish to take out a service cover plan as a service & labour are included. You decided not to & paid £150+VAT for a service upfront. When you booked you were told that if chemicals were required the charge would be £215+VAT. You were contacted the day before the service for payment & it was explained again that a top up would be £215+VAT. Once the service was completed it was confirmed that chemical was needed. You called to make payment but argued that you had previously been told £30. We explained there was a note on the system confirming that you were quoted £215+VAT but you put the phone down.
Central heating repair
Customer Service
Quality
Value
I needed AOS's help to repair a bent central heating pipe. Although the initial quote was high, they came and did the necessary work which turned out to be less than envisaged and so they reduced the fee without my asking. Tom (the engineer) turned up on time and worked without fuss. I was impressed by the fact that they didn't do anything unnecessary, for example the anti-freeze levels didn't in fact need topping up. Recommended.
Customer in Hertfordshire Posted on 10/02/2021 , work completed 05/02/2021
The trader replied (on 18/03/2021)
Hi David, Thank you for your review. AOS pride ourselves on being upfront and honest so we would always reduce our costs if not all the work was carried out. The same applies to the anti -freeze chemical, if a top up is not needed then we would never recommend for the sake of it. We are glad your experience was such a positive one. Kind Regards The AOS Team.
Professional throughout
Customer Service
Quality
Value
From start to finish a very professional service. Max and his team were polite, did a very good job and went the extra mile to do any of the little extras that might have needed doing - I was very impressed.
Customer in Cambridgeshire Posted on 06/02/2021 , work completed 03/02/2021
The trader replied (on 18/03/2021)
Thank you very much for your review. We will be sure to pass your comments of praise onto Max and his team. Kind Regards The AOS Team.
Air Source Heat Pump installation
Customer Service
Quality
Value
I was most impressed with the service provided by this company. The office staff were invariably helpful and knowledgeable and always responded promptly to my requests for information. The installation team were highly professional, efficient and friendly. They always kept us informed about what they were going to do and ensured that they left the house tidy and with access to hot water each evening. They also supplied electric fan heaters whilst the central heating was disconnected. When we experienced a couple of teething problems after the system was commissioned, these were rectifed on the same day that they were reported. I would highly recommend this company to anyone considering a similar installation.
Customer in Cambridgeshire Posted on 04/02/2021 , work completed 29/01/2021
The trader replied (on 18/03/2021)
Thank you for your positive feedback. We are so glad to hear that you were impressed with the high level of service AOS provided throughout your heat pump installation journey. It is of upmost importance to us that every customers experience is positive. please do let us know if we can be of any assistance in the future. Kind Regards The AOS Team.