Best new boiler to buy in 2020 Re December 16, 2019

Best new boiler to buy in 2020

Vaillant boiler

It’s time to replace your boiler, it’s an expensive piece of kit and you would rather spend the money on a holiday. You know it hasn’t been as efficient as it should be for a few years now, it’s time to replace it, save some money on your annual heating bills and get a more energy-efficient model that is better for the environment and heats your home better.

But where do you start? You want to make sure you get the right boiler for your property and get it at a good price too. In this article, we’ll take a look at the leading budget and premier brand combi, system and conventional boilers.

First, let’s look at the different boiler types so you can identify the type of boiler you currently have. We’ve covered this in a previous blog – ‘Boiler types explained’ if you want an in-depth explanation, but here is a quick summary…

Combi Boiler

This is the most common boiler type. A combi or combination boiler is named for its ability to provide both heat and hot water for your home. They don’t have any water storage tanks as they are connected to the mains water supply coming into your home, which is heated directly by some kind of dark magic that takes place within the boiler. 

Combi boilers are more economical as they only heat the water that you require. Many people that have older boilers switch over to a combi boiler when they purchase a new one.


  • No storage tanks in the loft or airing cupboard
  • Takes up less space
  • Economical
  • Cheaper to install than system and conventional boilers
  • Enjoy mains pressure showers without the need to install a shower pump


  • May not be able to produce enough hot water for multiple bathrooms in use at the same time.
  • Not all combi boilers are compatible with solar energy

System Boilers

System boilers can be found in homes with multiple bathrooms that could potentially require hot water provided at the same time. Water is heated and stored in a separate water tank, so it’s ready for use whenever it’s needed.


  • Ideal for homes with 2 or more bathrooms
  • Relatively easy to install
  • Doesn’t require a cold water tank
  • Compatible with solar thermal energy


  • Large storage tank required, not suitable for flats or smaller homes
  • Loss of heat from the hot water storage tank, no matter how well insulated
  • Hot water is limited to the capacity of the storage tank.

Conventional Boiler

Conventional boilers, also known as regular, traditional, heat only or open vent boilers, are the most difficult to install or replace.

A regular boiler includes both a hot and cold water storage tank, the boiler itself and an expansion cistern located next to the cold water tank. This takes up quite a bit of space in a home and it’s usually preferable to switch to a combi so that these tanks can be removed. 

They are also the least efficient boiler type and as they have more parts, there is more that could potentially go wrong.


  • Conventional boilers can supply hot water to two or more bathrooms at the same time and it won’t affect water pressure or heating.
  • An immersion heater can be fitted to the hot water tank to ensure you can still get hot water in the case of a boiler breakdown.
  • Conventional boilers are suitable for homes that suffer from low water pressure.
  • Compatible with solar energy sources in the same way as a system boiler.


  • Amount of space the boiler and tanks take up is impractical, particularly for smaller homes or flats.
  • Limited hot water up to the volume of your hot water storage tank.
  • Hot water tank loses heat, no matter how well insulated.
  • Difficult to install, only suitable as a replacement for another regular boiler system.

Hopefully, now you are able to identify which type of boiler you currently have and you can skip to the review section for the type of boiler you have. If you still aren’t sure what boiler you have then take a look at the video below.

Knowing what boiler you have is half the battle, the other half is knowing what size boiler you need. This is usually expressed in kW output. A kilowatt is a unit that is used to measure how much energy is output by the boiler in the form of heat. As a general rule, the more heat and hot water you require for your home, the higher the kW boiler you will need. 

At this point, you might be thinking ‘you lost me at kW output’, we get it, it’s boring and it’s stuff you don’t want to know but stuff you need to know. But do you? This is the beauty of the WarmZilla website, we do all the hard work for you and calculate what size boiler you need by asking you a few simple questions.

You can check out our boiler survey – the survey takes a couple of minutes to complete and we’ll give you an instant fixed price quote online.

If you want to learn more about flow rates and kW output for your home, here is an article we wrote for Big Bathroom Shop about choosing the right size boiler for your home

Ok, now we’ve done all the background work, we know what boiler type we have and we know about flow rate or we know that we can just take the WarmZilla survey and find out what size boiler we need. Now it’s time to take a look at the best boilers on the market for 2020.

We’ve broken the categories up into ‘best combi boilers’, ‘best system boilers’ and ‘best conventional boilers’. Within each boiler type category, we will recommend the best budget boiler and best premier boiler in each category.

This list was comprised by a team of heating engineers with a combined experience of over 50 years in the industry, but it is a subjective view. In searching for the best boilers in all the land we considered all of the major boiler brands including Worcester Bosch, Vaillant, Ideal, Baxi, Vokera, Heatline, Potterton, Glow-Worm, Rinnai, Alpha, Ferroli and Viessman. There are a lot of boiler brands out there but we felt this list covers the major brands.

Best Combi Boilers in 2020

Best budget range combi boiler

This is a fiercely competitive category with a good selection of reliable boilers at a very reasonable price scrapping it out for the ultimate honour of being crowned ‘best budget boiler 2020’. 

For 2020 our best budget combi boiler is the Vokera Excel

The Vokera Excel is an excellent boiler at a very cheap price, you can usually save between £300-£500 by purchasing a Vokera boiler. It comes with a standard 5-year warranty, giving you peace of mind. 

Our engineers believe that spending the extra £300-£500 on a new boiler is worth it as the boiler will last longer, will have less chance of breaking down and usually, you will also get better aftercare. However, times are hard and even a budget boiler is a lot of money to fork out on. 

It might be worth considering buying your boiler through one of our finance plans and spread the cost monthly, our plans start from as little as £10.68 per month.

We’d like to give an honourable mention to the Baxi Duo-Tec, great prices and award-winning customer service and also the Ideal Logic with great hot water output and an excellent TrustPilot score of 4.5.

This category was the hardest fought out of all and there were some differences of opinion but it was eventually agreed that the ‘budget’ part of the best budget buy was the most important factor and then a civilised cup of tea was had along with some accompanying chocolate hobnobs and all was well at WarmZilla HQ… until the topic of what the best biscuit was came up. But that’s a story for another blog.

Best premier range combi boiler

You’ll be delighted to hear that the winner for the ‘best premier boiler in 2020’ was unanimous and there was no arguing at all. Despite there being a few decent brands at the higher end of the market the decision was an easy one.

For 2020 our best premium combi boiler is the Worcester Style 8000


Worcester Bosch Lifestyle boiler

Whilst looks aren’t everything, this boiler is the best looking of the bunch, so if your boiler is in a visible area, then this big iPad-looking boiler is the one for you. Described by Worcester as the ‘Beautiful Beast’, it certainly lives up to its name. It’s by far the best-looking boiler out there and it’s the most powerful wall-hung boiler on the market.

It has all the same great features as the Life range, and it’s available in black or white. Engineers like it because it’s easy to fit, customers like it because it’s powerful and it looks good, and we like it because of all the previous reasons and despite it being fairly early on in its lifespan (they were only released last year) it’s been a reliable boiler so far and Worcester boilers, in general, are the most reliable.

Additional benefits include:

  • Improved LCD display for ease of use
  • Easy integration with smart controls
  • Very quiet boiler
  • Award-winning customer service
  • Established brand leaders
  • 10-year guarantee (when purchased through WarmZilla)

Best System Boilers in 2020

Best budget range system boiler

There were a couple of contenders for the best budget system boiler but it wasn’t too difficult a task to decide on the winner.

For 2020 our best budget system boiler is the Ideal Logic System

Ideal Boiler Installation

Whilst the Ideal Logic isn’t as energy efficient as the Worcester Bosch Greenstar it does come in about £100 cheaper. Some of the team argued that you would get that money back over the course of the boiler’s life in reduced heating bills and it would be better for the environment with the additional energy efficiency.

The Logic+ System boiler comes with a standard 7-year warranty if you were looking for a bit more cover. Ideal offers a good standard of customer service and if you were to need to ring their call centre you would stand a good chance of getting through, which always helps!

For these reasons, we as a nation have become increasingly sceptical of the ‘warranty’. But what if there was such a thing that guarantees any issues get fixed? Yes, you’ve guessed it, a manufacturer’s guarantee. But what is the difference?

Additional benefits include:

  • Queen’s award for enterprise
  • Built-in frost protection
  • Standard 2-year guarantee on parts and labour
  • SEDBUK A-rating
  • kW output boiler to suit every size home
  • Concealed pipe connections

Best premier range system boiler

The winner in this category was an easy choice, it has the best performance of a system boiler in its class, it’s got the highest energy efficiency and it’s available at a very reasonable price.

Our 2020 best premier system boiler is the Worcester Bosch Greenstar I System

What’s not to like about this boiler? It’s reasonably priced considering the performance, it comes with a standard warranty of 7 years (10 years when purchased through WarmZilla) and it’s A-rated, meaning you save money on your heating bills and it’s better for the environment. 

In addition, you get all the usual benefits of buying from Worcester Bosch – reliability, performance and service. It’s also won the Which? Best Buy award for the last 10 years running.

‘Reliability is the single most important consideration when buying a new boiler and Worcester Bosch has it in spades.’ – Which? Best Boiler Brands Report 2019

Additional benefits include:

  • A-rated energy-saving boiler
  • Award-winning customer service
  • Established brand leaders
  • 10-year guarantee (when purchased through WarmZilla)
  • Compatible with solar panels
  • Compact size allows them to fit in a kitchen cupboard

Best Conventional Boilers in 2020

Best budget range conventional boiler

As with all the budget categories, there are some great boilers available, all at similar cost and energy efficiency, so it was a tough one to call.

Our 2020 best budget conventional boiler is the Baxi 400 Heat

The Baxi 400 Heat boiler is our choice for the budget heat only boiler because it’s compact, suitable for homes of all sizes with kW options between 12kW – 30kW and it’s very quiet and lightweight. It’s an easy boiler to install, service and repair – so our engineers are a big fan. 

The only downside is that it has an energy efficiency rating of 89%, making it a B-rated energy efficient boiler. However, all of the other budget conventional boilers are also the same energy rating.

Additional benefits include:

  • Range of kW outputs to suit the size of your home
  • Energy Saving Trust endorsed
  • Very quiet boiler
  • Easy to install, service & maintain
  • Comes with a 5-year warranty as standard
  • Fits in a kitchen cupboard
  • NOx Class 5 boiler – better for the environment

Best premier range conventional boiler

The best in premier range will come as no surprise, it’s a brand and a model that has dominated the market for years due to its reliability, economy and output.

Our 2020 best premier conventional boiler is the Worcester Bosch Greenstar Ri

The Worcester Greenstar Ri only comes in around £100 more expensive than the Baxi 400 Heat but offers more reliability and energy efficiency. It’s available from a 9kW to a 30 kW output, meaning there is a size suited to whatever size home you have. Again, if you aren’t sure what kW boiler you need, don’t worry, just take the WarmZilla survey and all the boilers we recommend will be able to facilitate your needs.

But it’s not just its energy efficiency or price that make this boiler stand out – it has a fantastic flow rate too (litres per minute) – 4.9l @ 35°c on the 9Ri, but up to 12.2 @ 35°c on the 30Ri, that may not mean much to you, but trust us, it’s good.

It’s also one of the few A-rated energy-efficient conventional boilers on the market, saving you money on heating bills and saving the environment. There is no downside to this fantastic boiler, and all of our engineers have no hesitation in recommending it as our number one heat-only boiler in 2020.

Additional benefits include:

  • Range of kW outputs to suit the size of your home
  • Fits in a kitchen cupboard
  • 10-year guarantee (when purchased through WarmZilla)
  • A-rated energy efficient boiler
  • Excellent flow rates
  • Great value for money


You may notice that all of our premier selections for the best boilers in 2020 were Worcester Bosch.  Here at WarmZilla, we believe, like many others, that Worcester Bosch has long been and will continue to be the best premium boiler manufacturer in the market today. 

They have built up an enviable reputation for reliability and innovation across their product range and the introduction with the LifeStyle range in 2019 has cemented their position as market leaders.

There is a very good reason why Which? Have voted them ‘Best Buy for Boilers’ for the last 10 years running. But it’s not just the product that’s first class, they offer excellent customer service and with a highly trained WAI (Worcester Accredited Installer) network across the U.K, it means they are responsive if you need to make use of your 10-year guarantee.

The budget market of boiler is a lot more competitive, but given that it’s such a major investment, we would advise paying a little bit more to have that reliable brand name and the benefits that go with it. If you pay using one of our boiler finance packages, the additional monthly expenditure is quite minimal, and over the course of the boiler lifespan, you will earn your money back through added energy efficiency decreasing the price of your bills and the decreased likelihood of breakdowns and repair bills.

We hope our best boiler guide of 2020 has been of help in your quest for the perfect boiler, if you have any questions, just contact us; we’re always happy to help.

If you’d like to get an instant fixed price quote on a new boiler suitable for your home, then take our survey now, it only takes a couple of minutes and you’ll have an idea of how much a new boiler will cost you.

Write a comment
Your email address will not be published.