Category - Boilers
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Ryan Gill, Engineer

31 Jan : Updated 28 Nov ● 15 min read

7 signs you need to replace your boiler

A broken boiler is one of the last things anyone wants to wake up to first thing in the morning. Whether it’s going to stop you from having that much-wanted hot shower before heading to the office or leave you unable to turn your central heating on whilst working from home, faulty boilers can cause a whole raft of problems.

But how do you know if your boiler is nearing the end of its life and in need of replacing? To help stop you from worrying about the health of your home’s central heating, our team of expert boiler engineers have put together this guide. We’ll walk you through the main telltale signs that a boiler breakdown could be on the cards and, more importantly, what you can do to reduce the chances of it happening!

When to replace a boiler

As with all the other appliances in your home, your boiler will have a lifespan. Typically, modern domestic boilers should last for between 10 and 15 years, provided that they are serviced and maintained correctly. Ultimately, this means that if your boiler is approaching its 15th birthday, it’s possible that you might need to start thinking about replacing it with a newer model.

Now, it’s important to note that this is only an estimate. The answer to the question of when exactly you’ll need to replace your boiler will differ from manufacturer to manufacturer and be dependent on how well your central heating system has been maintained over the course of its lifetime.

As a general rule, boilers that have been serviced annually by a Gas Safe registered engineer fare far better than those that haven’t. An annual service means any issues that could cause your boiler to stop working can be resolved quickly and before they are allowed to develop into more serious faults.

Think your boiler might need to be serviced? Contact BOXT’s team of experts to book a home visit.

Should I replace or repair my boiler?

In some instances, you might not need to replace your boiler. If there is a minor fault or broken part that is causing it to malfunction, there’s a chance that this could be fixed simply by getting it serviced or replacing a particular part. The best course of action will depend on your individual circumstances, which is why it’s always worth getting an expert opinion on what the most effective solution is going to be.

Typically, newer boilers are prime candidates for being repaired rather than replaced. This is because you’ll still be able to source the parts needed to carry out the fix. The older your boiler, the higher the chances are that the components from which it’s built will have been discontinued.

What’s more, boilers do just degrade naturally over time! They are in use day in and day out, so after well over a decade of supplying your home with heating and hot water, they become less efficient and more susceptible to breakdowns.

Sometimes, the short-term cost savings that come with repairing a boiler don’t actually outweigh the longer-term benefits of replacing it with an upgraded model. Even though you might be tempted to try and avoid the upfront investment of buying a new boiler, this may just end up being a bit of a sticking plaster.  

Rather than buying new bits and pieces every month, it may be worth buying a brand new one altogether. Although it may seem like a lot of money, you’ll be saving money further down the line thanks to modern boiler technologies being far more energy efficient. 

At BOXT, all of the new and replacement boilers we sell are A-rated for efficiency, meaning they are designed to help you save money on your bills and reduce your home’s carbon footprint. 

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Signs that you need to replace your boiler

In some cases, a repair job just isn’t going to cut the mustard. Bigger, more serious issues might mean that a replacement boiler is the only way to go. Here are some of the biggest warning signs to look out for if you’re wondering whether you need to replace your boiler.

1. Leaks or dripping pipes

Your boiler can begin to leak in many places. To really pinpoint the exact problem, you need to know where your boiler is leaking from and whether a leaking boiler is an emergency or not.

The most common cause of a leaking boiler is a broken component inside the boiler. There are multiple water carrying parts within your boiler that could potentially leak. Sometimes it’s the actual component that is faulty or sometimes it could be something as simple as a damaged seal or O ring. Other common places you may find leaks include the pipes of your system. This can be due to corrosion, so it’s best to get in touch with an engineer who will be able to identify the problem correctly.

A leaky boiler could result in far more serious problems if it’s left unfixed. Water seeping into the system’s wiring can lead to electrical short circuits, or if the leak is large enough, it could even cause structural damage to your home!

2. Repeated low water pressure

Low boiler pressure can be caused by a number of things, including water leaks, bleeding radiators, expansion vessels that are faulty or have lost their air charge, or even a leaking pressure relief valve.

It’s easy to check the pressure of your boiler. All you need to do is look at the built-in pressure gauge; if the needle is below 1, you may well have a problem that needs addressing.

Read our complete guide to learn more about boiler pressure.

In some cases, low water pressure can be resolved by repairing your boiler or replacing the part that is leaking. This can cost anywhere from between £80, if it’s only the pressure release valve (PRV) that needs to be replaced, all the way to upwards of £600 if the entire heat exchanger is broken.

If you’re finding you’re losing pressure quickly, even when repressurising your system, get in touch with a Gas Safe registered engineer to find out if there is a more serious underlying problem at play. They’ll be able to advise you on what the best course of action is going to be so you don’t end up paying more than you should.

3. Banging or gurgling noises

Boilers can be noisy. Period.

Most of the time, the sounds and noises you’ll hear coming from your home’s central heating system are nothing to worry about. They can be caused by pipes expanding and contracting, water moving through the system and the boiler itself firing up. They can also be caused by a blockage or build-up of sludge, but this can be fixed by a power flush.

The important things to listen out for are any new, excessively loud or persistent sounds. If your boiler is making a kettling, banging, gurgling or clunking sound (especially if it’s accompanied by vibrations) then this can be a sign of a more serious problem.

If a broken component such as the system's pump is to blame for the sounds you’re hearing, trying to repair it might not be an option. To diagnose the issue properly, contact a Gas Safe registered engineer.

Want to know more about boiler noises?

Find out more...

Find out more...

Read our expert’s guide to the reasons why your boiler might be making a noise if you’re unsure.

Boiler noises guide

4. Odd smells

If you can smell something funky coming from your boiler, don’t try and ignore it by opening the windows or burning some scented candles.

A sulphurous or ‘eggy’ odour coming from your boiler is a sign that there is a gas leak. This can be incredibly dangerous, so it’s vital to turn your boiler off immediately and contact the National Gas Emergency line on 0800 111 999 for support. 

Sometimes, there won’t be a smell to warn you though. Carbon monoxide is a colourless, odourless gas that is potentially fatal if inhaled. If your boiler is leaking carbon monoxide, it’s going to need replacing. Signs to look out for include:

  • The flame burning yellow instead of blue
  • Deposits of soot collecting on and around the boiler
  • The pilot light frequently blowing out
  • People living in your home getting regular headaches, feeling nauseous or even dizzy.

If you suspect that there might be a carbon monoxide leak, turn your boiler off immediately and call the Gas Emergency line. We strongly recommend fitting a carbon monoxide detector in all homes that contain gas burning appliances.

Boilers can also produce a burning smell if an internal component is melting or burning. It’s possible that this can be repaired by just replacing the particular part that’s broken, but not always. If left unfixed, this could lead to the complete failure of your home’s central heating system, so it’s important to get it investigated by a registered Gas Safe engineer. 

5. You can’t find the parts needed

We’ve touched on this already, but older boilers are sometimes impossible to repair since the parts that are needed to do the job just aren’t in production anymore. If you can’t get hold of the components, replacing your boiler with a newer model is the only way to go.

Plus, even if you can find the necessary parts, they might be too expensive to make the repair worthwhile. If it’s a question of spending £1000 on new components or investing slightly more in a new boiler, the answer is never really going to be up for debate. A new boiler will be far more reliable and energy efficient than your existing system, plus it will be much less likely to need repairing in the near future.

6. Higher energy bills

Nowadays, boiler technologies are MUCH more energy efficient than their older counterparts. Boilers that are more than 10 years old might be G-rated for efficiency meaning that whenever they’re up and running, a considerable amount of the energy they use to heat your home will be wasted…not good for your pocket, or the planet. 

Modern condensing boilers are all A-rated for efficiency meaning that they make use of at least 90% of the energy they consume when generating heat and hot water for your home. If you’ve noticed your utility bills creeping up in spite of no major changes to your household’s energy usage, it’s likely that it’s time for a new boiler.

At BOXT, we’re on a mission to make the home heating industry fairer and more affordable for all. We have a huge range of boilers available at prices to suit your budget along with finance options and boiler subscriptions, too. Use our Find A Boiler tool to start saving money and energy today.

7. Not enough hot water

Even though your boiler may have been plenty big enough for your household’s heating and hot water needs when you purchased it, things change. Maybe your family has grown in the past few years meaning there are more bodies wanting hot showers in the mornings or perhaps you’ve extended your home and added another bathroom. 

Whatever the reason, if your existing boiler or hot water cylinder isn’t large enough to provide you with the hot water you need, upgrading to a larger model is probably the best plan. 

Before you select a new boiler and/or system, make sure you do your research to find out the types and models that will have the capacity to meet your needs. Larger homes with more radiators and bathrooms will typically need a system or standard boiler since these have a separate hot water cylinder. Combi boilers are more compact and, as such, are ideal for smaller properties.

Not sure what size boiler is right for your home?

We've got you covered...

We've got you covered...

Check out our complete guide. We cover how to work out what size boiler you need, what factors affect your decision and how to go about choosing one.

Check out our full guide

8. Frequent breakdowns

Provided that your engineer is happy that the reason for your boiler breaking down isn’t dangerous, any one-off issues are probably worth repairing. 

But, if your boiler is experiencing repeated breakdowns (something that becomes increasingly likely as it ages), it might not be economical to try and repair it every single time. Think about it this way; before too long, a series of £300 quick fixes will amount to the cost of a total replacement.

A top tip from our boiler experts is this: if you find yourself needing to call an engineer more than once a year (on top of your regular servicing) to fix new or recurring problems, it’s likely that a new boiler will make the most financial sense. 

If you don’t have the money to buy a new boiler outright, don’t worry. At BOXT, we have a wide range of finance options* available to help you spread the cost of your new energy efficient boiler over a period of months or even years. 

Or, with BOXT Life, our industry-first boiler subscription service, you can get a new boiler installed with unlimited servicing, repairs and replacements from as little as £35 per month. 

*Finance available subject to status. Terms and conditions apply.

The process of replacing a boiler

The process of replacing your boiler will depend on several factors, including the type of boiler you choose and whether it’s being installed in the same location as your existing boiler. Let’s take a look at replacement processes for each type of boiler.

Replacing combi boilers

Combi boilers, short for combination boilers, provide both hot water for your home in a single unit without the need for an external water tank. These are probably the most common boiler types in the UK, mainly because they are space-efficient and ideal for smaller homes.

Because gas combi boilers are the most popular type, they tend to have the most straightforward installations. If you’re getting a like-for-like replacement and having it fitted in the same place within your home, the entire process can take less than a day if the current boiler/flue positions and other variables are up to current installation standards.

Replacing standard boilers

Standard boilers, also known as regular or traditional boilers, require a separate hot water cylinder and cold water storage tank alongside the boiler itself.

Replacing system boilers

System boilers have components such as an expansion vessel and pump, meaning there is no need for a separate feed and expansion tank. They are often recommended for homes with more than one bathroom.

What to consider when replacing your boiler

A new or replacement boiler is a big investment, so it’s important to do your homework before making a purchase so you can be sure that the one you choose is going to be up to the job.

This is why we advise getting your boiler replaced before it gives up the ghost altogether. If your home is without heating and hot water, there’s going to be a lot of temptation to just rush into buying a new boiler without researching properly first. But, if you can plan in advance of this happening, you’ll give yourself plenty of time to shop around and explore your options before committing.

To help make the process of choosing a replacement boiler a little easier, we’ve compiled a list of the things you should consider to ensure you’re making a worthwhile investment.

1. The price

As a general rule of thumb, the advice is to choose the most expensive boiler you can afford. This isn’t just a money-making plot by boiler manufacturers and suppliers, either. Spending more in the short-term will, in the majority of cases, end up saving you money further down the line, since better quality boilers will come with longer warranties and life expectancies.

2. The reputation and reliability of the brand

Generally, new boilers are much more reliable than old ones. With upgraded smart technology as well as ‘A’ rated efficiency, investing in a brand-new boiler is not something you’ll need to do often.

Not all boilers are created equal, though. Some makes and models are infamous for breaking down and, as such, only come with 1-year warranties. Sure, the price tags might catch your eye, but you’ll likely run into countless problems before too long if you opt for a low-quality boiler.

At BOXT, we only stock boilers from the world’s most reputable brands and provide manufacturer-backed guarantees with all models. So, whatever boiler you choose, you’ll have complete peace of mind that it’s a reliable, high-quality piece of kit.

3. Your engineer

Now, we can’t stress this enough; you must not try to uninstall or install a boiler yourself. A Gas Safe Registered engineer is the only person for the job as they will have the experience and knowledge needed to do it safely and to a high standard.

When you buy or subscribe through BOXT, our team of engineers will sort the entire installation for you. They’re friendly and fully-qualified, so you can relax knowing that your replacement boiler is being fitted correctly. 

4. The future

Whilst 5, 10 or even 15 years might seem like a long way off, time really does fly and being prepared for the future will make sure that your investment in a new boiler is as worthwhile as possible.
Before choosing a boiler, consider whether there are likely to be any changes to your family’s heating and hot water needs in the coming years. Whether you’re thinking about having children or hoping to pack the eldest off to university, take everything into account to ensure your new boiler will still be the right one for your home in the future.

Need a boiler? It’s time to call BOXT

Here at BOXT, we’re committed to helping you find the perfect boiler for your home at the right price. Along with ultra-efficient models from the best-known brands, our team will be there with you every step of the way to make sure the whole process is a breeze.

Use our Find A Boiler tool to get free personalised quotes in minutes.

Whether you want to pay upfront, in smaller instalments or via a BOXT Life boiler subscription, we’re making it easier and more affordable for you to get the boiler you need.