The Worst Boilers In The Market: Which Brand You Must Avoid

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Last updated: October 31, 2023

Boiler brands are an essential component of the heating system in your home. If you live in a cold climate, or if you use your boiler for hot water and space heating, then you must have a reliable one. However, not all boilers are created equal. Some boilers will work better than others depending on the demands of your home’s heating system.

It is easy to find a good and reliable boiler out there in the market,  but it becomes a little difficult to find out the brands. A good and reliable boiler must be easy to maintain, affordable in price, and should provide all-around performance depending upon your requirements. Some examples of the best boiler brands in the market are Worcester Bosch,  Vaillant, and Baxi.

If you are looking for a boiler that is easy to maintain and provides all-around performance then you should choose between these three brands of boilers only. However, there is one more brand of the boiler in the market which is not up to par with other best brands of boilers out there in the market.

In this blog post, we’ll discuss some of the worst boiler brands to avoid so that you can get the most out of your purchase!

Category of the Worst Boilers

There are several ways to categorize the worst boilers in the market. One way is by the brands. Another is by their efficiency rating, warranty and price. So, without further ado, here are some of the worst boilers you can buy:

The Worst Boiler Brands

Let’s start with the worst boiler brands on the market. These are brands that you should avoid at all costs!

Ferroli Boilers

Ferroli is a brand that we see in many homes. It’s an Italian brand that produces both boilers and water heaters. However, their boilers are not very reliable. They have one of the worst failure rates in the market. Their boilers are not very reliable and they frequently break down after only a few years of use. Even if you’re able to get a Ferroli boiler working again after it breaks, be prepared for another breakdown shortly.

The most common problems users usually deal with the Ferroli Boiler are:

  • Leaking – Unfortunately, Ferroli boilers don’t have well-made shut-valves, which make them prone to leaks. You will most likely have to deal with a leaking boiler if you buy a Ferroli. With the majority of Ferroli boiler types, the most popular trouble fixers are called to repair is this.
  • Loss of pressure – Because the boiler loses pressure regularly, the expansion vessel within it must be repressurised from time to time.
  • Boiler locking out – This may be caused by a design or manufacturing error on the Printed Circuit Board (PCB). The PCB replacement usually solves the problem.

These are some of the most common issues that you might experience with a Ferroli boiler. If you’re considering purchasing one, be sure to keep these in mind!

Vokera Boilers

Vokera is another brand that you should avoid. Their boilers are often unreliable and can be expensive to repair. It is essential that you look at consumer reviews before buying one. One of the most negative reviews received of the Vokera Boilers models is the Vokera Vision 30C, which has an alarming number of negative reviews.

The majority of the complaints concern various problems with the boiler, including:

  • Lukewarm water – The diverter valve on Vokera boilers is a pain to operate. The most typical issue after a diverter valve checkup is the valve getting jammed and preventing the water from heating uniformly.
  • Poor hot water performance – If you’re looking for a boiler that provides good hot water performance, then Ferroli is not the brand for you. Many users have complained about the poor hot water performance of their boilers.
  • Noisy boiler – A noisy boiler can be quite frustrating, and it’s one of the most common problems with Vokera boilers.
  • High fuel consumption – High fuel consumption is a very common complaint about Vokera’s range of modern condensing boiler types, and it can be quite frustrating for anyone trying to save money on their heating bills!
  • Unreliable – Many users have complained that they’ve had problems making repairs to their Vokera boilers and that they’re often very unreliable.
  • Boiler not firing – This is generally caused by a lack of air or incorrect gas pressure.
  • No water or heating – Because the pipe is not adequately insulated, condensation builds up in the winter and freezes. This can cause the boiler to fail.
  • Boiler ‘puffing’ – The sounds of your boiler puffing are due to a flue issue. This is usually the case in Vokera boilers since the flue has come loose or is corroded. In most situations, the flue system needs to be replaced.

If you are considering purchasing a Vokera boiler, be sure to consider these issues before making your decision. You don’t want to be dealing with these problems down the road. Otherwise, you might find yourself with an expensive repair bill shortly!

Related Post: Vokera Boiler Problems

Worst Boilers based on Efficiency Rating

Efficiency rating is another way to categorize the worst boilers on the market. The most inefficient boiler brands are typically the cheapest ones, and they tend to break down more often than more expensive models.

One of the most essential things to think about when selecting a boiler is efficiency. It refers to the amount of energy consumed by the boiler while providing heating. The more efficient the boiler, the more money it saves and has a smaller environmental effect.

In 2018, new legislation required that all new boilers meet a minimum efficiency of 92%. That means you can be certain of at least 92% efficiency regardless of the type or brand of boiler you purchase now. There is little difference between boilers, no matter what sort of brand you choose.

There are no worse boilers, in terms of efficiency. Also, many homeowners fail to keep track of the performance of their boilers, and there haven’t been many bad reviews based on boiler efficiency.

Worst Boilers based on Warranty

Warranty is another important factor when it comes to buying a boiler. The warranty of the boiler often indicates whether or not you can expect reliable service from your new appliance in the long run.

The length of the warranty is generally a good indicator of the boiler’s quality. When looking at the length of the guarantee, bear in mind that it may differ from brand to brand. Customer reviews can provide you with a clear picture of customer service quality and let you know how previous consumers felt about their boiler breaking down under warranty.

Right now, Bosch Worcester has one of the most generous warranties in the business. It is not only a ten-year guarantee when the boiler is bought from an authorized dealer, but it is also a ten-year warranty. This is a testament to the fact that Bosch offers some of the best products in this market. Other boilers such as Viessmann, Baxi or Vaillant offer similar warranties with their boilers, but they do tend to be more restrictive.

Related Post: Best Boiler Warranties

Worst Boilers based on Customer Service

Another crucial part of the boiler is customer service. When a customer has an issue with their boiler, they need to have someone reliable and trustworthy who can come to fix it as quickly as possible. In general, most brands provide decent after-sales support for customers who require repairs or maintenance work.

That being said, some brands are more reliable than others when it comes to customer service. If you are looking for a brand with exceptional customer service, then you might want to avoid Viessmann and Main. Both of these brands have been known to take weeks or even months to come out and fix a boiler that is under warranty.

Worst Boilers by Price

Price is another factor you should take into account when purchasing a new boiler. The most expensive boilers are not always the best, but they do tend to have more features and be more reliable than cheaper models.

When looking at the price of a boiler, it’s important to remember that installation costs will also be incurred. You can expect to pay anywhere from £750 to more than £1600 for the installation of a new boiler.

There is no such thing as ‘the worst boilers’. You will find that with most brands, there are quiet and rather expensive models available alongside noisy and cheaper ones. Most people’s budget determines their choice, but it can be difficult choosing between good quality and a cheap price.


In conclusion, there is no one-size-fits-all answer when it comes to the worst boilers. The best thing you can do is assess your own needs and find a boiler that meets those specific requirements. Do your research, read customer reviews, and ask for advice from professionals to make an informed decision about the best brand of boiler for your home.

At the end of the day, it’s important to choose a brand that you can rely on to provide efficient and reliable service for many years.


  1. Most and Least Reliable Boilers – Consumer Reports