Combination (or ‘combi’) boilers are a popular choice in UK households, accounting for well over half of all new domestic boilers fitted in the country each year. These compact appliances serve as a central heating boiler and high-efficiency water heater in one, hence their name. As well as saving space, these boilers deliver hot water to showers and taps at mains pressure with no need for a pump. 

How long does a combi boiler last

It’s certainly not hard to understand their appeal, but how long can you expect a combi boiler to last in your home? The answer to this will depend on a range of factors, including the quality of the appliance and how well you look after it. Keep reading to find out why you should select your next boiler with care, and how regular servicing can make it last longer. We also suggest some simple fixes that may help if you spot a problem with your boiler, and outline how much you can expect to pay to get a new one.

What is the typical lifespan of a combi boiler?

These boilers can differ widely in terms of their quality and longevity, and it’s important to be aware of this when you’re searching for a new model for your home. Saving money in the short term by opting for the cheapest model you can find may ultimately end up costing you more if the boiler you choose isn’t made to a high standard.

Generally speaking, you can expect modern boilers to last for around 15 years, or potentially even longer if you get a good quality model and service it regularly. Pay attention to the warranties offered with boilers, and to benefit from added peace of mind, consider getting an extended warranty if possible. For example, many Viessmann boilers, including our Vitodens 111-W combi model, are available with extended warranties of up to 10 years.

Do combi boilers need servicing?

Servicing your boiler will cost you, but it’s a worthwhile investment as it will likely save you money in the long term, both in terms of your boiler itself as well as energy efficiency. Getting this appliance assessed by an engineer once a year (or more often if you notice any problems with it) will help to ensure it stays in good working order. During a service, your engineer will conduct important checks on everything from the heat exchanger to the electrical connections and seals. They will also ensure your boiler is operating at the right pressure, replace any damaged or worn parts and clean components as necessary. Read our complete guide for homeowners to learn more about what is included in a boiler service.

Identifying and fixing any problems quickly through regular servicing can help you to avoid bigger and more expensive faults further down the line. It can also play an important role in optimising the lifespan of your appliance. On the other hand, if you skip services, you could be storing up trouble for the future. You may also invalidate your warranty.

Servicing is essential in terms of safety too. Arranging regular checks of this appliance will minimise the risk of potentially dangerous faults going undetected, such as carbon monoxide leaks.

How can I fix a combi boiler?

If your boiler suddenly stops working or develops a fault, this doesn’t necessarily mean you need to order a new one. Many problems can be fixed, and sometimes the solution is surprisingly simple. If you’re wondering how to fix a combi boiler, here are some suggestions that can help you to address basic problems.

Looking to replace your gas boiler?

Reset the timer

If you’ve experienced a power cut recently, the timer on your boiler may have reset without you realising it. The fix for this is a straightforward timer reprogramming. If you’re not sure how to do this, check the instruction manual provided with the appliance.

Check the pressure

To work effectively, combi boilers need to operate at the correct pressure. If the pressure is too low, your boiler may not heat your home properly, while if it’s too high, there might be a problem in the system that could cause serious damage if left unresolved. Most gas boilers have an operating pressure of 1-1.5 bar, and this is usually shown on the pressure gauge as a green zone. If the gauge on your appliance is showing there is a problem with the pressure, you may be able to adjust it yourself by following the instructions in the manual.

Reset your boiler, or check the pilot light

If your boiler has a reset function, try using it to see if this brings it back to life. If the appliance was made before 2004, it will probably have a pilot light instead of a reset function. Check to see if this is on. If it isn’t, you may be able to relight it yourself using the instructions in the manual.

Turn up the temperature

If your heating isn’t coming on when you expect it to, try turning your room thermostat up to 21℃. It may simply be that your heating is failing to come on because your rooms are already at the desired temperature.

Defrost the condensate pipe

If it’s cold outside and your boiler isn’t coming on, it may be that the condensate pipe is frozen. You can check this by locating the pipe where it exits your house to run into a drain. If the pipe is frozen, pour warm water over it until the ice has melted. You can then reset your boiler and it should start working as normal.

If these suggestions don’t fix the problem, or if you notice a more serious fault with the appliance, make sure you call in a heating engineer to take a look.

How much is a new combi boiler?

New combi boilers vary in price. The amount you pay for a new appliance will depend on a range of factors, including the brand, specification and size of boiler you go for. Also, bear in mind that as well as factoring in the cost of the boiler itself, you’ll need to budget for installation.

The cost of a new combi boiler for a small property tends to be in the region of £600 to £1,500, while for a terraced or semi-detached house, you can expect to pay between £700 and £2,000. Appliances that suit detached homes generally come in at between £900 and £3,500. Meanwhile, for installation, simply replacing an existing combi may cost approximately £600, while semi-replacing a conventional boiler is likely to be more expensive at around £700. To install a combi boiler in a new location, you can expect to pay around £1,100.

If you’re getting extras with your new boiler, for example a power flush of your existing heating system, a new thermostat or new radiators, you will also face additional costs for these.

When buying a new combi boiler, you might find you’re tempted to go for the cheapest option, but this can prove to be a false economy. Make sure the appliance you select is designed and built to last, and get it fitted by a Gas Safe registered installer. By doing this, and getting the appliance serviced regularly, you will ensure it lasts for many years to come.

Even if your boiler is not approaching the end of its life, you may wish to consider updating it earlier as part of a plan to make your home more energy efficient - particularly if you are making changes to your property such as new insulation, adding solar panels or implementing a smart home package. The cost of your boiler replacement may well be significantly offset by the immediate energy savings you could experience.

Our most popular combi boilers

Vitodens 050-W gas condensing boiler
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Vitodens 050-W
A compact, low-cost gas condensing boiler

With compact dimensions, low weight and quiet operation, the attractively priced Vitodens 050-W gas condensing boiler will integrate effortlessly into any living space. Which? Best Buy, Vitodens 050-W 29 kW Combi.

  • Up to 7 years
    warranty
  • Easy control with
    LCD Display
  • Smart Home
     with tado°
  • Boiler Plus
    Compatible
Vitodens 050-W

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