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Condensing Boilers Prices

Condensing Boilers prices vary from £500 to £1,700 depending on the brand or output.

Condensing boilers prices vary dependent on your budget.  You can, for example, buy a perfectly good condensing boiler from a top brand, such as; Baxi, Valliant, Potterton, Worcester Bosch or Glow Worm, for less than £700.  These would, however, despite being of an incredibly high standard, have limited energy output if you are looking to provide heat for a larger home.  

What is a condensing boiler?

What is a condensing boiler?  As opposed to being a specific type or brand of boiler, the name ‘condensing boiler’ is rather in reference to the process, which includes condensing wastewater vapour, in order to retain its latent heat.

This method was first championed in the UK in April 2005, when the government passed a law insisting that all gas-fired boilers, installed into new builds or as a replacement for old boilers, were condensing; later, in 2007, this became applicable, too, to oil-fired boilers.

This move was made as part on an initiative to make energy use in the UK more efficient, and it has recently been further supplemented by a Europe-wide gas boiler efficiency standards.  This new development has introduced a ranking system, in which only condensing boilers will be awarded the top ‘A’ grade.

Level of Efficiency

It is claimed by many leading manufacturers that thermal efficiency levels of up to 98% can be achieved.  This is in comparison to traditional designs, which can commonly only achieve between 70-80%.  At the very least, condensing boilers are able to achieve 90% efficiency.

Conventional boilers in the UK, which still make up four-fifths of the total UK market, produce ⅙ of the nation’s CO² emissions.  The new Eco-Design Directive, which runs concurrently with the recently introduced European boiler standards, is said to be capable of cutting emissions by up to 400 million tonnes, annually, in the EU.

Ultimately this is part of the EU’s focus of achieving a 20% improvement in energy efficiency, in the 15 years between 2005 and 2020.

How Do They Work?

The increased efficiency achievable is really quite simple:

  • Conventional boilers lose energy through water vapour,
  • By condensing this vapour the boilers reacquire its latent heat,
  • Such boilers are, thus, capable of increasing energy efficiency by a considerable amount,

The success of this conversion is, however, dependent on a number of different variables, which include; design, materials and installation.  Thus, new technologies are constantly being developed to improve efficiency, reliability, cost, and durability.  This potential level of improvement is also outlined within the new EU standards, which will evolve once more in 2019 to include a new ‘AAA+’ level, which will only include ‘super-efficient’ boilers.

How Does This Benefit Me?

Fundamentally, efficiency is directly proportional to price.  In other words, the more efficient your boiler, the cheaper your energy bills.  This is, of course, also reliant on reliability and access to services, so this must also be considered when purchasing your boiler.  Above all else, in addition to saving money, by cutting your household CO² emissions, you also do your own little bit to protect the planet.

What is the Difference between Output and boilers pricing?

The more energy your boiler produces, the more expensive it will be. For example, the Greenstar Highflow 550CDi – available at £1972.44, produces 41.1 kw of energy; compared to the much cheaper Baxi Neta-tec 24 HE Combi Boiler, which produces 24 kw and is available at £666.62.

Here are some further  comparisons of condensing boilers prices and energy output of a select few top quality models.

ModelEnergy Output (kw)Typical Price
Worcester Bosch Greenstar Highflow 440CDI44/55£1,644.39
Glow Worm Flexicom sx31£900
Valliant EcoTec Pro 24 NG24£744.86
Baxi Duo-Tec 24 HE24£726.48
Potterton Promax 12HE Plus Slimline11.8£553.72

What are the Other Factors to Consider?

Not only does energy output influence condensing boilers prices, so to does a boiler’s dimensions, flow rate and efficiency rating.   Everyone’s boiler requirements differ according to your home needs.  What you want from your condensing boiler for you and your home will influence the price the price you pay.  The first step is to have a Gas Safe engineer assess your home and help you determine exactly what model is most suitable for you.

Why Do I Need a Condensing Boiler?

New building regulations now enforce that every new property build have a high energy efficient condensing boiler installed.

The reason behind this enforcement is because both the UK and EU insist you will save both money and energy in the long term.  Condensing boilers, as opposed to be being a specific make or brand, are rather called so because of the system they use within the heating process.  Quite simply, waste, in the form of water vapour, is reacquired by the boiler in the form of condensation, and thus its potential energy is retained.


  • Highest energy efficiency SEDBUK rating – up to 90%
  • Cuts heating costs by up to £130* a year
  • Comply with new legislation


  • More expensive than other boiler types
  • Condensing boilers can go wrong and be costly to maintain
  • Technology is complex therefore finding an engineer to fix any problems might be difficult