Searching for the best boilers is so 2024. What are 2025's worst boilers?
In the market for a brand-spanking new boiler? If you want the best, go for a Worcester Bosch.
If, for some reason, you want to know about the worst, read on.
If you’re certain the worst boiler is in your house right now, we feel for you. Perhaps we can cheer you up with an instant quote and a fixed price for your new boiler and installation.
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How we whittled down the worst boilers
To keep things unbiased, there's many ways to carry out a fair comparison between boilers, so, in the interest of objectivity, here are the factors we considered:
Which? Annual Boiler Survey Results
Warranty period offered by the brand
The overall reputation of the brand based on customer reviews
TrustPilot reviews
Awards and accolades e.g. Which? Best Buy Awards
Customer service performance
The price range of their boilers
Efficiency ratings
In all honesty, we might have taken bribes into consideration, but no boiler company bothered to even try.
Which? Annual Boiler Survey Results
The trusted name in consumer research, Which?, carries out an annual boiler survey (that's every year), totting-up survey results from over 12,000 boiler owners and 166 heating engineers, combining the daily user experience and the expert opinion.
In total, the survey considers and provides a final aggregated score for the following:
Reliability score
Customer score
Engineer recommendation
Build quality
Availability of parts
Ease of fixing faults
Ease of servicing
No other organisation surveys and collects so much data about plain old boilers, so, you can trust Which?.
So, what did this year’s survey results show? Which boiler was the worth of boast worlds?
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Based on the survey results, there was a clear loser – Ferroli boilers.
Based in Burton-on-Trent, this Italian brand received a low score of two out of five from consumers and just one star from engineers. The brand also received three out of five for reliability. It probably doesn’t help that the brand sounds like an off-brand Ferrari. You know, the way your grandma might buy you some Hair Pod earbuds for Christmas.
Score | |
Overall Reliability | 3/5 |
Engineer Score | 1/5 |
Consumer Score | 2/5 |
Overall Ferroli landed an overall score of just 35%, significantly lower than any other boiler brand, including Vokera, who came second to last with an overall score of 50%. If this were a race, Ferroli wouldn’t have made it past the first corner.
In particular, the review of the Ferroli HE 27C, highlighted no positives at all, furthermore, other models offered by the manufacturer include HE 32C and the HE38C.
Combined, these combi boilers are officially the worst boilers rated and reviewed by the trusted consumer organisation.
Worst for Boiler Efficiency
A boiler's efficiency rating relates to how much 'energy efficiency' is the percentage of the total energy used by the boiler to provide useful heating.
An efficient boiler will save the planet and money. It's a cliché win-win.
Central heating boiler efficiency is categorized using a system called the Energy-related Products (ErP) rating system, where A represents the most efficient to G, represents the worst efficient. At this G level, your boiler heats the entire planet instead of just your water, while also burning through your money.
Since 2018, Boiler Plus legislation has meant that all new boilers are required to be at least 92% efficient. This means that no matter which brand boiler you select, it will always be at least 92% efficient.
Essentially, this means that in terms of efficiency, there is very little difference between new boilers. Buying a new boiler always avoids the equivalent of using a flamethrower to heat up a swimming pool so you can make one cup of tea.
There really is no worst. Boiler plus legislation took the fun out of this category for your benefit.
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Worst Boiler Warranty
The boiler manufacturer’s warranty is one of the most important considerations when looking for a new boiler.
Generally, the length of a warranty reflects the quality of the boiler, but it is also worth mentioning that the level of support can vary.
That is why it is important to check customer reviews, to get an insight into what their breakdown experience when under warranty was like.
Please note that if customers describe their own breakdown experience, it might say more about them than about their boiler.
Is your boiler's warranty worth the paper it's written on?
Boiler manufacturers do not typically offer the same warranty period for all of their products, but they typically begin at around 1 year.
The aim is to purchase a boiler that comes with a warranty that lasts as long as possible. A one-year warranty is about as useless as getting an additional 20% air after filling your tires.
Currently, Worcester Bosch offers one of the best warranties of any manufacturer. Not only is it a 10-year warranty (if purchased through Heatable), but it is a guarantee.
Boiler Guarantee, Boiler Warranty...What's the Difference?
A guarantee is an agreement from the brand that they will attend to your property and repair or replace the condensing boiler within a reasonable timeframe.
Most other brands just offer a warranty as standard, this is an agreement to investigate the problem but is not an unconditional agreement to fix or repair it for free.
You could argue that Worcester Bosch loves taking care of your boiler the way your mum loves you. We just hope your mother never imposed a 10-year time limit.
We guarantee Worcester Bosch offer the best guarantee
Worst Boilers by Price
The cost of the boiler is an important consideration, but ultimately, it is never a good idea to buy the cheapest, since the Which? survey results show you may be trading off quality, reliability and much more.
Buy cheap, buy twice?
With that said, here is a list of some of the most popular boiler brands with a list of their typical price ranges.
Bear in mind that this is for the boiler only and does not include installation costs.
Learn all about combi boilers in our what is a combi boiler guide.
Price (Boiler Only) | Brand Type | |
Vokera Compact 25 | £600 | Budget |
Ferroli Sky Eco | £550 | Budget |
Heatline Capriz 24 | £500 | Budget |
Alpha E-Tec 28 | £900 | Middle Range |
Vaillant EcoTEC Pro 28 | £1,200 | Middle Range |
Viessmann Vitodens 050 | £1,000 | Middle Range |
Worcester Bosch Greenstar | £1,200 | Premium |
As can be seen in the table above, the cheapest boilers are offered by Ferroli and Vokera, while Viessmann, Worcester and Vaillant are the most expensive. It also shows that Worcester is underselling their boiler, but let’s not tell them.
There is a clear trend that the manufacturers with the best reputation and reviews by Which? are more expensive, so in the case of boilers, it is definitely worth paying a little more.
So, which boilers do Heatable recommend?
Now we have discussed some of the worst boilers available, based on a variety of different factors, you are probably wondering which boilers are the best.
For the full, detailed analysis, check out our best boiler manufacturers guide and best combi boilers article.
The very best boiler does your dishes for you, walks the dog, and raises your offspring as outstanding citizens. Unfortunately, you still need to do those things, but at least you’re not manually heating your water anymore.
Essentially, the best boilers actually available are the ones that are reliable and offer longevity and a warranty period that provides long-term peace of mind.
Worcester Bosch boilers ranked top of our list for several reasons, not only have they been a Which? Best Buy awards winner for 10 consecutive years, but they offer an unrivalled 10-year guarantee (not just a warranty).
Combine that with their excellent guarantee offer, customer service and easily sourced parts and you have the best boiler brand in the UK.
Get a fixed price on a new Worcester Bosch Boiler, online.
Worst boiler conclusion & some key takeaways:
If you are looking for a new boiler, it is important to consider the cost of installation and any other associated work you may require.
The good news is that we offer a fixed price for the complete installation, which includes the boiler and installation.
Get Quotes for the Best Boilers
If you’re aiming to get the best deal on a new boiler, consider getting a quote from us, here’s why:
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Price match guarantee: We will match any like-for-like cheaper quote.
Flexible payment options, including interest-free finance.
Up to 12-year guarantee on selected boilers.
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