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Combi boiler

Replacement gas boiler

Boilers account for 60% of our home’s energy bills, so it’s important to ensure your system is working efficiently and won’t encounter any problems down the line.

Gas boilers can breakdown or fault at any time, leaving you without heat or hot water until the problem can be fixed. And unfortunately there is never any warning of when an old boiler will breakdown.

Boilers over 10-years-old are more prone to problems and repair bills can exceed £300. Given you could be saving money every year on energy bills and limit the risk of a breakdown, a replacement gas boiler could be your answer.

Benefits of a gas boiler replacement

Gas boilers are at the heart of your home, providing you with heat and hot water all year round. This makes a breakdown even harder for the general dynamics of your property.

With a replacement boiler:

  • Reduce your heating bills by as much as £300 a year. Inefficient boilers could be working at just 70%, meaning you’re paying out a lot more annually than you should be. Efficient condensing boilers burn fuel more efficiently, producing a greater amount of heat.

  • Cut your home’s carbon footprint by up to 1,220kg a year, helping the environment with global warming problems and aiding the Government in meeting EU targets.

  • Heat your home more efficiently and ensure heat is distributed evenly. When a new boiler is installed you’ll often receive other services such as a power flush to remove sludge build-up.

Combi boilers

Combi boilers or combination boilers are the UK’s most popular replacement gas boiler installation, with over 50% of new systems being a combi.

Combi gas boilers are highly efficient condensing boilers, converting more fuel into usable heat. This is made possible with a larger flue, which captures more of the hot gases and prevents them from escaping.

Combi boilers are also popular because they provide homeowners with hot water on demand, scrapping the need for water tanks in the loft or airing cupboard. This also means you’ll save plenty of room in your home.

Gas boiler quotes

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Average Combi boiler cost

The common cost of replacing your gas boiler is £3,005. Costs vary based on the type and brand of boiler you choose as well as the contractor you decide to go with. For example, a small local business may be able to offer a better price than a large national company as they will have fewer overheads. It' best to get a range of quotes from different boiler engineers so you can compare prices, reviews and references before going ahead.

Average price per Combi boiler job in 2024

Avg. price low

Avg. price low
£1,504

Avg. price

Avg. price
£3,005

Avg. price high

Avg. price high
£4,488

£4600

£3450

£2300

£1150

£0

Prices based on actual Combi boiler costs for your area, as reported by local Quotatis members.

Combi boiler installation cost in your area 2024

Labour cost £1,750
Material cost £625
Waste removal £125
Time frame: 1-2 days

Advantages for Combi boiler

  • Lower gas bills each month with the more efficient modern combi-boilers
  • When we replace a boiler, the controls usually need an upgrade, too - Modern controls allow you to adjust the heating from your smart phone
  • Option to heat water and central heating seperately. Allowing you to just have hot water in the summer
  • No more waiting for the cylinder to heat up: there’ll always be hot water whenever you need it
  • Modern boilers are often smaller than older types. Give you extra space

Disadvantages for Combi boiler

  • Annual boiler services are highly recommend and essential if installed in a rental property
  • Carbon monoxide is produced during operation, faulty boilers could leak this into the property
  • If you don't have gas already then there will be an additional cost to connect gas to your home

Combi boiler Manufacturers

Combi boiler FAQs

How do I know if my gas boiler needs replacing?

If your boiler is making strange noises or smells, or doesn’t seem to be working properly, it may need replacing. Boilers usually last about 10-15 years. Even if your boiler is working normally, it’s worth replacing when it gets this old. An annual check will establish if there are terminal problems with a boiler that cannot be fixed.

How does the A-G gas boiler rating system work?

The A-G scale refers to the energy efficiency of your boiler. G-rated boilers are the least efficient, and give you less heat and hot water for your money. Installing an A-rated boiler will reduce your energy bills and carbon emissions. Don't compromise on cheaper, lower rated boilers, you will save yourself more money longer term with an A-rated model.

What size boiler do I need?

The size of boiler you need will depend on the size of your home, how many radiators and bathrooms you have and how many people live there. The boiler size refers to its output, which is measured in kilowatts (kW), rather than the actual dimensions. Speak to your boiler engineer about which boiler is suitable for you, as if you have more than one bathroom or a lot of people in your home a combi boiler might not suit you. Other boiler types such as system boilers or conventional boilers may be better suited to larger homes because they have bigger outputs.

How long does it take to replace a gas boiler?

In the UK, more than 50 percent of the money paid for utility bills is aimed at heating and hot water costs as stated by the Energy Saving Trust. This also means that when you settle for an old or ageing boiler, you’ll have to unnecessarily incur high utility bill in order to heat your home and have hot water on demand. In this kind of situation, the most effective and practical solution is to fit a new gas boiler in your home. This will provide you several benefits such as improved efficiency and reliability as well as reduced operating costs.

However, the only drawback here is the fact that removing your old gas boiler and replacing it with a new gas boiler isn’t a 5 minute task. And as you would have expected, like many other home improvement project there’s always an element of disruption that you’ll have to put into consideration when fitting a new gas boiler system. Good news is, with a qualified and experienced heating companies, these disruptions can be kept at a minimum. So now let’s take a look at how long it’ll take to replace a gas boiler depending on the type.

✓ An existing combi boiler upgrade - Installation times may vary, but typically the removal of an existing combi boiler and installation of a new one will usually be completed in a day - about four to six hours.

✓ Converting a regular to a combi boiler - Due to the fact that these type of project is usually labour intensive, it’ll take longer to complete - about 2 days.

✓ First time installation of new boiler to a home. This will usually take about 3 or more days because new pipes and other tasks need to the installation will be carried out.

How does a gas boiler work?

A boiler is simply the most important part of a central heating system as it generates the heat that warms up the home or property. Basically, the appliance or small furnace makes use of gas, LPG or oil in order to fuel its operation. However in the UK, most boilers are usually fuelled by natural gas which is supplied automatically from the national gas grid. And depending on how it operates, there are various types of boilers.

Typically, a gas central heating boiler will have multiple pipes entering from underneath. While one pipe supplies the boiler with gas from the mains gas supply, another pipe allows cold water to enter the boiler to be heated, the last pipe then enables hot water to exit the boiler so it can be distributed around the home.

✓ There are fuel jets and heat exchangers inside the boiler. When the heating is turned on, a valve is opened to allow the mains supply gas to enter a sealed combustion chamber in the boiler. There are multiple little valves which permit the entry of the gas before being ignited by an electric ignition switch. These jets heat a metal component in the boiler known as a heat exchanger which works to transfer the heat to the cold water pipe and heat up the water.

✓ Once the water has been heated to the target temperature, it’s then pumped through a circuit of pipe which runs around your home by an electric pump.

✓ The heated water enter each radiator, is then transmitted via a closed loop and radiates heat into each room.

✓ Once done travelling through all radiators, the water then returns to the boiler at which it must have been cooled. Therefore, the boiler will have to reheat following the same process before circulating. The water can only be drained by a professional Gas Safe engineer

How much is a new combi boiler?

If you’re thinking about getting a new combi boiler, you may be wondering just how much it’s going to cost so as to start making preparations as soon as possible. However, providing a precise cost for the acquisition and installation of a new combi boiler is simply impossible as combi boiler prices vary greatly in price - usually ranging between £1500 to about £3500 based on the brand of the combi boiler, the insurance or warranty, installation, your location as well as the size and power of the appliance. Due to the fact that combi boilers are compact units which doesn’t need a hot water cylinder or a cold water tank to produce heating and hot water for homes, it’s a very popular type of boiler that’s frequently used especially in the UK.

Combi boilers are also widely known to be the most energy efficient type of boiler because they are able to provide an instant supply of hot water anytime you turn on a tap. Combi boilers particularly perfect for flats and houses where space is limited as they have the ability to deliver instant heating and hot water without requiring any extra parts or components.

In the event whereby you’re about to choose a combi boiler for your home or property, it’s always advisable to compare models as well as prices from only the most reliable and sought after brands across the globe. Depending on the manufacturer, the overall quality of the boilers as well as their prices can differ. However, regardless of your budget, you’ll discover there are a plethora of combi boilers available in the market that’ll also suit your taste.

How long does a gas boiler last?

When it comes to gas boilers, this is one of the most frequent questions that always pops up and for a good reason. When you invest a considerable amount of money to acquire and install a gas boiler in your home or property, it’s only reasonable not only to expect the boiler to warm up your home efficiently, but also to do so for a long period of time. If you’ve just bought or about to get a new gas boiler, it’s likely you won’t have to worry about getting a replacement for a lengthy period of time. Several gas boilers will last for anywhere between 10 to 15 years on the average. However in the event whereby you have an existing one that’s fast approaching the end of it’s useful life, then you should know the time go get a new gas boiler is just around the corner, and the earlier you make the purchase, the better (to avoid any surprise breakdowns that’ll leave your home super uncomfortable).

Just like any other home appliance, it’s a fact that an older gas boiler ( especially those that have been installed over a decade ago) are significantly less efficient that the new modern ones. When the older versions were manufactured is a completely different time to now as both technology and climate concerns are wide apart. So when your existing boiler is approaching the end of it’s useful life, it’ll be wise to start saving up to cover the cost of getting a new one. However, if it’s only about 5 years ago your boiler was installed, it’s highly likely to still be very efficient.

How long does a boiler last?

If you get the right size boiler for your home and you get it serviced regularly, your boiler could last up to 15 years. It may even last longer than this, but you’ll find that your boiler begins to become less efficient as it gets older. Also, as technology improves, a boiler older than 15 years may not be the most efficient one on the market.

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