How to tell if my boiler needs replacing

When it comes to replacing boilers, remember, age is just a number. There’s a misconception that when a boiler reaches a certain milestone you need to get rid of it and have a new one installed. This really isn’t the case. With a few tweaks and regular servicing, your boiler can live well into old age. However, in some situations, there’s no alternative to "out with the old and in with the new".

Take a look at this list of boiler-on-the-blink signs. Understanding them will help you work out whether your trusty old boiler may need repairing or replacing.

1. Frequent breakdowns

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If you’re having to call out a Gas Safe engineer more than once a year, it’s worth considering whether the sum of repairs and call-outs is greater than the cost of a new boiler.

Treating your existing boiler to regular servicing should keep it ticking over smoothly all year, so a replacement is really only needed if your boiler still struggles afterwards.

2. Your bills are creeping up without explanation

You’ve probably heard about the "efficiency rating" of boilers, but you may not know what it means for your household bills.

Simply put, a less efficient boiler costs you more money to run. Modern boilers are A-rated and operate at more than 90% efficiency, while G-rated models run at 70% or less. Learn more from our handy guide to boiler efficiency.

While upgrading from a G to an A-rated boiler could save you around £200 a year (and may be better for the environment), the cost of a replacement boiler can run to about £2,300. So it’s worth weighing up what you’re spending.

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3. Your boiler or radiators are noisy

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Central heating systems make all sorts of sounds, most of which are completely harmless. But it’s worth noting any changes in noise type and volume.

Tapping sounds on pipes or radiators could be a sign of "sludge" build-up in your system. This is easy to fix with a Powerflush. But if you hear humming, vibrating or banging, a bigger fault may exist within the boiler or central heating system. Let your engineer know if you’re hearing any unusual boiler or central heating noises.

4. The blue flame is now yellow

Your boiler flame should burn bright blue. If it’s changed to a yellow or orange colour, your boiler needs an immediate service from a Gas Safe engineer. They’ll be able to tell you how serious the problem is, and the best way to resolve it.

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5. Your boiler smells odd when it’s on

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If you smell a sulphurous, eggy odour when you use your boiler, there’s probably a gas leak. Immediately turn off the boiler and call the emergency gas line on 0800 111 999. Then get in touch with a registered Gas Safe engineer. Do this if you ever detect any unusual odours emitting from your boiler. Learn more in our guide to boiler safety. In this situation, your boiler may well need replacing. Consider the advice of the engineer carefully.

6. Your boiler leaks

Your boiler shouldn’t ever leak water. If it does, an internal component — such as a valve or seal — may have broken. Leaving a problem such as this unfixed could lead to an electrical short-circuit, and even structural damage to your home. So switch your boiler off and have it professionally checked. Hopefully, it’ll be possible to restore it to full working order, without the need to replace it.

How much does a new boiler cost

7. Replacement parts are hard to find

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If your boiler is in its "golden years" it might be hard to find spare parts when a repair is needed. This doesn’t mean that you need to rush out and buy a new boiler, but it does mean that some careful research on the cost and availability of spares is worth doing.

If it’s very expensive to replace obsolete parts, consider how often you need to do this. A real workhorse of an old boiler might hardly ever have issues, in which case, it’s probably worth repairing. If your Gas Safe engineer needs to scour the internet for new parts on a regular basis, the mounting cost of repairs could mean it’s more economical for you to replace the boiler instead.

8. It’s not working like it used to

Despite its yearly service, at some point your boiler might stop doing what you need it to do. If your radiators are taking a lot longer to warm up than they used to, or you’re having to continually adjust your boiler’s pressure, it could be time for a new one. Before forking out, however, it’s worth checking that there isn’t a build-up or blockage in your system preventing it from working properly. A Gas Safe engineer will be able to take a look at it and determine whether it’s a minor issue or your boiler is beyond repair.

How much is a new boiler

If you’ve decided that a new boiler is the right option for you, see our guide to the different types of boiler. It talks you through combi vs conventional and more. There’s also a handy guide to boiler installation considerations.

If you want to give yourself a sense of how much a new boiler costs, book a free appointment and one of our heating advisers will come and give you a fixed price quote.