Green Central avatar

Written by

Last updated:

ATAG IC Economiser Plus 27kW Combi Gas Boiler Review:

ATAG IC Economiser 27 Plus Combi Review & Prices

In the U.K., a boiler breakdown happens to 1 in every 5 UK homes each year. That equals between 5-7 million U.K. boiler breakdowns, an almost staggering number and all of which cause immense financial misery and stress. 

If you are one of these unfortunate souls and you need a new boiler then you really need to find a reliable and efficient new boiler system with a long-lasting warranty. 

Comparing the ATAG IC Economiser 27kw Plus Combi Boiler

 Compare Boiler Quotes are here to help you in this immense quest of finding the best new boiler which will heat your home and hot water for years to come.

Today, we are looking at a brand that we have reviewed before but in this case, we are reviewing a smaller yet highly capable system with a fantastic reliability factor. The ATAG IC Economiser Plus 27kW boiler is the focus of today’s article.

We’ll be looking at the company, the main features, the warranty, and our overall score and recommendations. 

This could be one of the best combi boilers in terms of energy efficiency, so let’s dive right in!

A Little About ATAG Boilers:

ATAG heating technology logo

ATAG has been a premier boiler manufacturer for decades. In fact, they have been manufacturing and designing boilers for 70 years now. During this time, they have set new standards for high efficiency, service, and engineering. 

ATAG are exceptional when it comes to boiler manufacturing and adaptation. What is different about ATAG, is the fact that they install and design boilers for most countries in the world, each with different engineering standards.

This has led to the development of the ‘i’ series boilers. These are built to exacting standards with only the best quality steel and brass components.

According to ATAG, they offer the most energy-efficient boilers in Europe, with the lowest NOx emissions. 

They especially make a lot of headway into the market with their newest iCon heat exchanger. This heat exchanger, made from stainless steel, is rated to 98% efficiency and able to retain the efficiency over years of continuous use.

This means this getting a quote for this new boiler can lead to lower bills and less maintenance.

Introducing the ATAG IC Economiser Plus Combi 27kW Boiler:

ATAG IC Economiser Plus 27kW Combi Gas Boiler Review:

The ATAG IC Economiser 27Kw Plus Combi gas boiler is a highly efficient and reliable combi boiler system. 

The 27Kw system is perfectly suitable for 1-3 bedroom apartments and homes with one bathroom. It is on the smaller end in terms of output but is perfectly capable of heating up to 10 radiators simultaneously. This unit also delivers a competitive flow rate of up to 12.6 litres per minute. 

The compact dimensions of just 700x440x355mm mean it’s perfect for homes where space is limited. 

Being a Combi boiler means that it does not require an external water tank or cylinder (which is another great space saver) and will produce hot water on demand.

The ATAG is also known as being incredibly efficient with an ERP rating of A. It also impresses further with an efficiency level of 94%. It generates such efficiency by recycling the flue gases for the second time rather than losing the energy as waste, hence it being a condensing boiler. 

Please note also that higher output ratings are available including 35kW and 39kW to suit larger homes with a higher demand for hot water and heating.

One of the key features, like with the Viessmann Vitodens recommended boilers is the included and unique to AGAG, iCon heat exchanger with an amazing lifetime replacement guarantee. 

Plus, an outside weather compensator is standard. 

The Warranty:


This is a highly reliable boiler and is represented by the fact that ATAG offers a 10 year warranty to give you peace of mind that your boiler will last for years to come. As a standard warranty, it competes with other high-end systems from Viessmann and other manufacturers.

This will be included in the new boiler cost and 10 years is pretty much the standard these days. 

IC Economiser 27 Features at a Glance:

ATAG IC Economiser Plus 27kW Combi Gas Boiler Review:
  • Achieves ErP ‘A’ rating for heating and hot water
  • Savings of up to £320 off your gas bills
  • Further savings on hot water bills
  • Compact dimensions (mm) h700 X w440 X d355
  • Flow Rate of 12.6 L/m
  • 10 year warranty including all parts and labour
  • Powered by the unique iCon heat exchanger with a lifetime replacement guarantee
  • Instant hot water with pre-heat facility
  • Built in Passive Flue Gas Heat Recovery Device
  • Comes with an outside weather compensator as standard
  • Can be used with the ATAG ONE smart controller
  • Built in frost protection
  • Quiet in operation due to bottom-up modulation
  • Completely user friendly
  • Typical Price (inc VAT) £2,000
  • Typical installation Cost (inc VAT)* £500 – £1,000
  • Total Cost £2,500 – £3,000


As a small home combi boiler, we would highly recommend this system. It is a wonderfully constructed system with high quality components, high efficiency, and a decent flow rate. Where it really shines is the 94% efficiency with a 10 year warranty, making it one of the best in the industry. 

 In terms of other recommendations, we always come down to the systems which we think outperform what we are reviewing and lately we think the Viessmann systems come out on top. In this case, however, we think that the ATAG matches the Viessmann with a similar high quality stainless steel heat exchanger.

The competition that we would suggest to you would be the Viessmann Vitodens 050-W combi boiler as it is cheaper, with similar features and a 10 year standard warranty,all with a higher,  up to 98% efficiency rating and therefore further annual heating savings. 

If you are interested in this boiler or are looking at having a boiler quote then please look at our partner site Boiler Central. Simply answer a few questions about your home and they will provide you with a quote calculator, and the best boiler for your home specifically. 

After you have a quote and choose your boiler, you can pay online with flexible financing, book a convenient installation date, and wait for the installation of your next new boiler.

Boiler Central also offers affordable boiler cover which can cover your boiler, and central heating, and even provides an annual boiler service with selected plans!

Hot Deals Icon
Green Central avatar

Written by

Read some of our superb solar panel installation reviews from Trustpilot

Recently had solar panels fitted by Green Central and I can’t speak highly enough of the team. The whole experience has been trouble free and I would recommend them to anyone thinking about having solar panels installed – 10/10!

Rob Schofield


Our installation is now complete! 8 solar panels fitted and the journey from initial consultation through to the end product has been seamless.
Hats off Green central, Credit where it’s due.
Will definitely spread the word!



Recently had six solar panels fitted on my house by Green Central and I couldn’t have asked for a better service. In particular, I have to highlight the exceptional communications through out, the over all smooth running process and completely stress free experience, all down to Green Central. I now have grid independence which is valuable beyond estimation.


Name *
Email *
Phone No. *
Post Code *
Name *
Email *
Phone No. *
Post Code *