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How much does a combi boiler cost?

combi boiler

Effective and efficient heating of homes and water are an essential part of our modern world. Combi boilers, as the name suggests, combine both hot water and central heating requirements in one boiler. Unlike standard boilers, there is no water storage tank involved. Instead, hot water is offered on demand making combi boilers both economical and effective. In order to suit all customers, combi boilers are available in a choice of gas, oil, electric or LPG fuelled versions. Many more gas and oil models are available to choose from than electric or LPG.

Three cost considerations should be taken into account when evaluating the suitability of a combi boiler for your application. Firstly the purchase cost of the combi boiler unit. Secondly the installation and fitting costs involved, and thirdly the maintenance and running costs throughout the lifetime of the unit.

The size of the property to service will determine the required KW output of the unit. Small houses or flats up to 27kw, medium houses 28kw to 34kw and large houses 35kw upwards. Building regulations dictate that most installations require a condensing boiler. Only in special circumstances are non-condensing boilers permitted to be installed. The unit prices included below are just a selection of the many available. Prices are accurate at the time of writing - please contact the vendor directly to confirm the price is still current.


  • Worcester Greenstar Heatslave 2 12/18 Floor Standing Oil Fired Combi Boiler 12-18kw. £1636.95 ex VAT
  • Warmflow U-SERIES Kitchen / Utility Condensing Combi Oil Boiler 15-21kW. £1691.46 inc. VAT
  • For narrow spaces, Firebird Enviromax C26 slimline combi boiler 20-35kw. £1514.79 ex. VAT
  • For external placement, Worcester Heatslave External 25/32 Floor Standing HE Combi Oil Boiler, 18-32kw. £2593.90 inc. VAT
  • Trianco Eurostar Oil Combi Boiler 20/26kW Internal 70-90 BTU 2532, 20-26kw. £1804.78


  • Heatline CaprizPlus 24KW, Gas. £399.17 ex VAT
  • Worcester Greenstar 24i Junior Combi Boiler, LPG, 24kw. £831.66 inc. VAT
  • Glow worm Ultracom2 30CXI Combi Boiler Natural available in Gas or LPG, 30kw. £826.78 inc. VAT
  • Baxi Platinum 33 HE, Combi Boiler, Gas boiler, 33kw. £1128.00 inc. VAT
  • Main 24HE Condensing Combi Boiler, Gas or LPG, 24kw. £636 inc. VAT
  • Sime E-Comfort Plus HE Condensing Combi Boiler, Gas or LPG conversion kit available, up to 31.5kw. £559
  • Ariston Clas HE High Efficiency Combi Boiler, Gas or LPG conversion kit available, 24kw. £1275 inc. VAT and fitting
  • Biasi Riva Advance 32HE Combi Boiler, 32kw. £679
  • Glow-Worm Ultracom2 35cxi combi with standard flue & clock, 35kw. £1073.35 ex VAT


  • Elnur CMX15 Electric Combi Electric Boiler 15kw 1 phase. £1797.60 inc
  • Heatrae Sadia Electromax 9Kw Underfloor Electric Heating Boiler & Store, 14.9kw. £1280.79 ex VAT
  • Gabarron CMX15 Electric Combi Boiler, 3-15kw. £1713.60 inc. VAT
  • EHC Fusion E10 Electric Storage Combination Boiler 15kW with 150 Litre Cylinder, 15kw. £2212.52 inc.
  • ACV Etech W 36 Electric System Boiler 36kw 3 phase. £1716.00 ex VAT. 15w single phase version is also available.


Naturally the costs to install a new combi boiler, or replace an older existing version, will vary according to your requirements. Combi boiler installation is not a DIY job and it is vital to remember that gas appliances must be installed by a Gas Safe Engineer. Oil appliances should be installed by a member of the Oil Firing Technical Association (OFTEC). Electrical appliances should be installed by a qualified electrician.

Installation and fitting costs of a combi boiler

The first point to consider is the location of the boiler. Your boiler may need moving if you are replacing a non-condensing boiler with a condensing one. In this case, new pipework and the inclusion of a drain must be factored into the installation cost. Locating your new boiler could cost anything from £0 to £1000.

Regulations also dictate energy efficient controls must be installed. This usually means installation of thermostatic radiator values which could add up to £700 to the installation costs. For gas installations, a new supply pipe is also usually required to comply with new regulations, at a cost of up to £1000.

The existing heating system should be flushed prior to the new combi boiler being installed, which is a process which ensures sludge and dirt in your existing radiators is removed. Failure to do this flush could void your new combi boiler warranty, though the cost involved is around £500 for an average sized house.

To summarise the installation costs, if you are simply replacing an existing boiler with a combi boiler, with no major changes to the area you can expect the overall price to be around £600 to £800. If some minor work is needed to fit the new boiler, the price will rise to around £1000. Should new radiators be needed, this will add approximately another £600 to the job. However, if you need a new boiler where no current pipework or electrical points exist, or need complete removal and replacement, this is a far larger job and will set you back around £1500 to £2500.


Spare parts prices vary wildly. Genuine parts are always recommended both for durability and validation of warranty. The length of warranty also varies. To save future costs, look for a model with a lengthy warranty. Some companies are confident enough in their product to offer a full 5 years, and occasionally as much as 10 years. Yearly servicing is essential for a long boiler life. Expect a yearly service to cost around £80-90 for parts and labour for a service without problems.


This is a usual question and it is important to know when time to get a new boiler is.  Firstly, you need to determine the energy efficiency rating of your existing boiler.

Secondly, you have to look at the age of your boiler. Boilers last up to 10 years. Older boilers generally gain from having sturdy cast-iron heat exchangers, and have fewer components than newer models.

 If your boiler is approaching that age, then consider about replacing for a new one. Boilers the older they get, the harder they have to work to heat your home. And this means they are less efficient, give more problems and the risk to fail is higher.

Boilers represent a significant investment, and they are an important expense if you want a strong and secure central heating and hot water system.

Your boiler is very important; we can say the heart of your home and is a very complicate to work with it. But, don´t worry this is our job to take care of your worries!

Our professional traders´ will help you in every problem, so you can get your wished boiler installed.


We know that when time comes to install a new boiler can turn your budget upside down, but you don´t have to worry because you have the possibility to choose boiler installation quotes from four home improvement companies.

Installing a boiler offers you the possibility to reduce your heating bills and to heat your home more efficiently.

Installing new combi boiler

Another advantage is that you have even more free space, because the modern boilers are smaller than their older counterparts and you have more possibilities for siting them on walls rather than floors.  If you want to have even more space you can even hide them behind a kitchen cupboard.


The cost of a boiler service depends on a number of factors that you need to consider before booking an engineer. Factors such as: the area that you live in, the boiler type and even the time of the year can affect the cost of your boiler service.

Your location affects the cost and it depends on the distance that exists from your home to engineer home. When someone is looking for a quote, we send home improvement companies’ in your specific postcode, in this way you have an accurate idea of how much a service will cost in your area.

The best period to get your boiler services is in summer and spring when the interest is lower. In general, the homeowners choose to change their boiler in autumn and winter but the services are cheaper in low season.

The competition is important because if there are a lot of qualified engineers in your area, you may find that boiler service and repair costs are lower, due to high levels of competition in the marketplace.

Depending on boiler types you choose the cost can vary. Normally, oil boilers cost 

Boiler service costs can vary between boiler types. Typically, oil boilers comparatively with gas boilers service cost more .Our advice is to compare all quotes from all professional trades' people that we send as prices normally differ from town to town.


This subject depends on what type of boiler do you have, what do you use your hot water for in the summer, and what appliances you may use. If you want to cut your energy bills you can switch off your boiler and relying on other sources for your hot water.

The hot water will be used in the kitchen for cleaning the dishes and in the bathroom for washing, but if need to use hot water out the tap then maybe you won´t be to turn your boiler off.

One way to save energy is to buy modern dishwashers and laundry machines because have the ability to heat up water as it enters into the closed system.

You can have hot water at your kitchen if you have a combi boiler with only changing your boiler setting to only provide hot water and not heating. This way you have hot water where you need it, but the radiators won´t come on.

However, you should run your central heating for a few minutes once a month during the summer. This way you keep the system in working order.

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