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How Long Do Boilers Last?

Sep-2020 / 6 min read

Reading Time: 6 minutes

Your boiler is a heavy-duty machine that works around the clock to provide hot water and heating to your home. In a country as cold and damp as the UK, it plays a vital role in your central heating system. Even summer nights can run a bit chilly. Given its importance and frequent use, boilers are built to last and are considered a long-term investment for every home and business.

Whether you are buying a new boiler or just curious when your boiler replacement is due, you are bound to ask yourself, “how long do boilers last?” There is no strict answer to it. Their lifespan purely depends on how much you use your boiler, whether you take care of them or not, and sometimes, just pure luck. If you want to make the most out of your current boiler, it is important to learn how long they last and what factors affect that.

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How Long Should A Regular Boiler Last?

No matter what type of boiler you have, the average lifespan would be around 10-15 years. With the proper care and maintenance from a boiler engineer, they can last well up to 20-25 years, though there may be dips in performance. For most boilers, this dip happens in the 10th year. Their efficiency goes down about 30% by then. 

The efficiency of your boiler depends on what type you have. Combination (combi) boilers and condensing boilers are some of the more modern options. A combi boiler can have a thermal efficiency of 98% when they are new, and a condensing boiler can have 92-95% depending on the model and brand. However, if you have a traditional boiler on hand, like oil boilers or gas boilers, they usually have a thermal efficiency of 85%

There have been so many great strides in improving heating systems’ efficiency that it was only 30 years ago when these oil heating furnaces could only reach a maximum of 70% when bought new. 

Can you imagine the 30% dip in the 10th year with such an inefficient model? It is understandable to see why most would replace it in 10 to 15 years. However, given the push for more sustainable options, you might see a generation of boilers that can last well beyond that, given proper maintenance. 

How Do You Extend The Life Of Your Old Boiler?

Like any other appliance in your home, the only way you can extend its lifespan is through responsible use and proper maintenance. When you manage to do both consistently, there should be no reason for such heavy-duty machines to break down before their time. 

What Commonly Affects Its Lifespan

Several things can negatively affect your boiler’s lifespan–it is a mixture of environmental factors and user habits. It is up to the homeowner, or the landlord and tenant’s joint effort, to make sure that these variables are under control. 

 Improper Boiler Storage

When you first get your unit, the boiler manufacturer’s manual outlines your boiler’s ideal location and storage. It is generally advised that you keep it in a cool, dry place away from other items for proper ventilation.

If your boiler is in the attic, basement, or closet, make sure your boxes and clothes are not directly beside your unit. Leave at least 1 m or 3 feet-gap between your boiler and other items. However, it is preferable to keep the whole area clear. 

*You may also want to apply the same idea for your boiler flues and vents. It is always best to keep them clean so that they can do their job properly. 

Impact Damage 

Even though your boiler is built to last, they aren’t made for impact damage. The impact can come from a variety of sources like items falling on your unit or receiving hits when you roughhouse near the boiler. While your cast iron boiler might look like it can take a beating, that isn’t true. You may need to replace the section or the entire boiler because of the dents in extreme cases.

Poor Water Treatment

Poor water treatment leaves impurities and debris in the system. These tend to build-up and create blockages in your storage tank and pipework that affect your existing boiler’s performance. When the grime stays inside too long, it can lead to a boiler breakdown. The UK generally has hard water, which means it is rich in minerals and similar sediments. You need to treat your water for this before it enters your home to prevent this. 

Debris Build-Up

As mentioned earlier, debris can affect your boiler and lead to its early retirement. And poor water treatment isn’t the only way to trigger this. When there is trapped air in your system, it can mix with the water and create rust. Rust, along with the limescale from your hard water, can turn into a thick sludge that prevents your home from heating evenly. It becomes something that not only damages your boiler but your pipework and radiators as well. 

You may want to invest in a magnaclean filter, and you can read more about it here. 


Every boiler has set limits. While you can go for the maximum amount, you cannot keep it there indefinitely. You are at risk of overfiring your boiler the same way you would overfire your woodstove. Cast iron boilers are more prone to this. 

Remember, your unit is only built to withstand a certain amount when you keep overfiring your boiler, you damage the internal tubing and heat exchanger. The reality is that overfiring doesn’t actually speed-up your heating. So, you end up increasing the wear on your unit without any reward. 

Thermostat Misuse

When you set your thermostat to a certain temperature, it works hard to keep it that way inside your home. So it doesn’t matter if it becomes warmer or cooler because the thermostat sensors will adjust the heat for you. If you increase the heat to account for the sudden drop, you are only overfiring your older boiler, and that counts as thermostat misuse.

Another example is when you constantly toggle the controls or participate in “thermostat wars” with your partner or roommate, that also contributes to decreasing your boiler’s lifespan. It forces your boiler to make frequent changes, and there might be a point where it can no longer keep up. 

Delayed Repairs

Nothing affects the boiler as much as neglecting repairs. For the most part, when the issues listed above happen, a quick and speedy repair can make things right. They rarely leave lasting impressions on your system. However, when you leave them alone, the worst-case scenario always happens, and you end up without heating when you need it the most. 

Plumbingforce offers clients same day service for emergency boiler repairs. If you want to address your heating problems as soon as possible, all you have to do is look for our experience boiler engineers!

How To Take Care Of Your Boiler

When it comes to taking care of your boiler, it is a balancing act. You need to be able to avoid making common mistakes while actively working to address its issues. You can set preventive measures in place, like a self-administrating anti-limescale solution and a magnaclean filter. There are a host of maintenance tips without calling an engineer:

  • Adjust the boiler pressure

  • Bleed your radiator

  • Drain and balance your system

  • Invest in a smart thermostat

By doing this, along with scheduling an annual maintenance check-up with your local heating engineer, you can make your boiler last longer. If you are looking for a new, professional team – Plumbingforce can match you with a Gas Safe registered engineer.

Connect with the best local plumbers and boiler engineers near you

When Should You Replace Your Boiler?

Most people think they should replace their boiler after 10 years. After all, that’s when efficiency starts to go down. However, machines aren’t like perishable food items. When they are well-cared for, they can last past their “expiration date.” Instead of basing your replacement on its years, keep an eye out for your broken boiler’s tell-tale signs:

  1. High gas/ fuel bills
  2. Noisy boiler and radiator
  3. Difficulty sourcing replacement parts
  4. Frequent breakdowns
  5. Fails to heat your home and water adequately

When these signs become commonplace, and you have your engineer on speed dial, you may be due for a replacement. 

How Much Does A Replacement Boiler Cost?

The cost of a replacement boiler depends on your boiler type (modern condensing boiler vs non-condensing boiler), brand (Viessmann boiler vs Worcester Bosch boilers) and model. They can cost anywhere from £500-2,500 for most household brands. For a more comprehensive look, you can learn more about replacement boilers here. 

*Note: The boiler price range listed is only an estimate and can be subject to change. Before your boiler installation, it is best to consult your heating engineer about the best option for your home. While you are at it, you can also get a free quote from your boiler installer to make sure you have the best price. 

While boilers are notoriously expensive, think about the savings you make along the way. You can enjoy lower fuel and energy bills and less frequent visits from your heating engineer. If you cannot find the budget for your replacement boiler, you can look into the UK’s green initiative for their new boiler grant. The grant allows residents to get a free boiler or have one heavily subsidised. You can take your pick from the sustainable options available like an electric boiler, combination boiler, or condensing boiler.

When it comes down to it, you can last without a boiler for long, especially given the UK’s winters. It is always best to treat them well and consider their long-term role in your home. If you need a helping hand, you can book your Gas Safe engineer online or call us at 0330 162 5329! No matter what type of boiler you have, a non-condensing boiler, system boiler, conventional boiler, gas boiler, or combi boiler, Plumbingforce can be your go-to service!

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