How often should I replace the boiler? 7 signs to look for

Whether you have high energy bills or you've been hearing some strange noises, there are often a few indications that you could do with an upgrade.

As we approach Spring (and hopefully) some warmer weather, we should be less reliant on our heating systems.

This means that engineers are less busy with callouts and we should see the financial pressures of winter start to ease off. 

In other words, it's as good a time as any for a boiler replacement if you should need one.

But what are the signs yours is due for an upgrade?

How often should you replace your boiler?

Andy Kerr, Founder at BOXT commented on the dangers of old boilers: “Old boilers are not only less efficient than newer boilers, but they can also lack the safety features of modern boilers, making them more dangerous.

"Over time, boilers become prone to malfunctions, which can increase the risk of leaks or even carbon monoxide emissions.

"The average boiler can last between 10-15 years if well maintained with yearly services, so, if your boiler is reaching its 15th birthday it is time to start thinking about a new one.” 

“The older your boiler is the higher the chances are that the components from which it’s built will have been discontinued, meaning that boiler repairs may be harder and more expensive to complete. 

"If your boiler is showing these signs you may need to replace it.” 

What are the signs that I need a new boiler?

Here are the seven signs you need to look for, according to the experts at BOXT.

Leaks or dripping pipes

The most common cause of a leaking boiler is a broken component inside the boiler.

Multiple parts within your boiler could potentially leak, sometimes it is an actual component that is faulty or sometimes it could be something as simple as a damaged seal or O ring.

It may also be within the pipes of your system which have corroded. The best way to identify these problems is to get in touch with a boiler engineer. 

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. 

Low water pressure 

Low water pressure can be caused by water leaks, bleeding radiators, faulty expansion vessels or even a leaking pressure relief valve. 

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 £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 find you’re losing pressure quickly, even after 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.

It’s making strange noises

Boilers can be noisy. Most of the time, the sounds you’ll hear coming from your home’s central heating system are nothing to worry about.

They can be caused by pipes expanding, water moving through the system and the boiler firing up. 

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.

You can smell something odd 

If you can smell something odd 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.

Carbon monoxide alarms are essential in every household as they can detect a potential leak as early as possible, warning you before it reaches dangerous levels.

If you suspect that there might be a carbon monoxide leak, turn your boiler off immediately and call the Gas Emergency line. 

You can’t find the parts needed

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 likely be far more reliable and energy efficient than your existing system, plus it will be much less likely to need repairing in the future.

Your energy bills are higher 

New boilers are much more efficient, with boilers over 10 years old potentially having an efficiency rating as low as G.

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 despite no major changes to your household’s energy usage, it’s likely time for a new boiler.

Recommended reading

• Why does my boiler pressure keep going too high and how do I lower it?
• How often should you service your boiler? Best time to book it in revealed

• Ignoring this common boiler 'red flag' might cost you £1000s

Frequent breakdowns

 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.

Before too long, a series of £300 quick fixes will amount to the cost of a total replacement.

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, a new boiler will likely make the most financial sense.