Best Combi Boilers
If you are looking for the best combi boilers available, you will find the results below.
We have compiled a list of the most reliable and trusted boilers in the UK to help you decide which boiler is right for you.
If you need help deciding which type of boiler is best for you, chech out the guide we created: Which is the best boiler to buy for my house?
Which are the Best performing Combi Boilers in the UK
We understand that investing in a central heating system is one of the most costly purchases for your home.
You want to be confident that the boiler you choose will be hassle free and last for years to come.
We want to help you find the best performing combi boilers so that you can heat your home with the least problems or downtime.
According to boiler owners and expert engineers, Worcester Bosch have come out top of the best boiler brands in the UK.
The boilers listed below have been tested by thousands of users. The ratings have been provided by Which consumer magazine in 2018.
We believe the survey carried out by Which magazine offers the most reliable rating if you are looking for the best combi boilers available in the UK.
Worcester Bosch Combi Boilers
Greenstar Heatslave II ErP +
Brand: Worcester Bosch
Type: Oil Combi
Typical Price: £2,327.00
Rating: 92%
Outputs available (kw): 18, 25, 32
Dimensions (mm) height x width x depth: 855 x 520 x 600
Greenstar Heatslave II is the most popular boiler by leading manufacturer Worcester Bosch.
This sleek, modern combi boiler is perfect for small, medium or large-sized homes. Suitable for homes with one or two bathrooms.
This eco boiler will work with a range of green energy sources including solar and wood-fired boilers.
The compact smart design makes it easy to fit below a standard kitchen worktop.
Greenstar Heatslave II
External ErP +
Brand: Worcester Bosch
Type: Oil Combi
Typical Price: £2,437.00
Rating: 92%
Outputs available (kw): 18, 25, 32
Dimensions (mm) height x width x depth: 950 x 640 x 770
Suitable for large, medium and small-sized homes, the Greenstar Heatslave II External ErP + can be installed outside of the home.
If you are looking for the best external combi boiler, Greenstar Heatslave II is rated as the highest performing.
With all the same features as the internal model, this robust boiler will work provide hot water in all weathers.
Worcester Bosch Greenstar I ErP
Brand: Worcester Bosch
Type: Gas Combi
Typical Price: £1,059.00
Rating: 90%
Outputs available (kw): 27, 30
Dimensions (mm) height x width x depth: 690 x 390 x 280
If you require a small and light boiler with high output, The Greenstar I Compact ErP offers a complete solution for your home.
The innovative heat exchanger fitted in these boilers provides improved reliability and efficiency.
One of the best gas combi boilers for 3 or 4 bedroom homes.
With reduced energy use, and the ability to be used with Greenskies solar panels, this heating system will save money on energy bills.
Greenstar Si Compact ErP
Brand: Worcester Bosch
Type: Gas Combi
Typical Price: £927.00
Rating: 90%
Outputs available (kw): 24
Dimensions (mm) height x width x depth: 690 x 390 x 280
The Greenstar I Compact ErP is designed to fit small, single bathroom households. The compact size makes it perfectly sized to fit into a kitchen cupboard.
With easy to use controls, you can adjust the heating to suit your comfort preferences.
One of the best combi boilers for 1 or 2 bedroom homes.
Greenstar CDi Compact ErP
Brand: Worcester Bosch
Type: Gas Combi
Typical Price: £1,210.00
Rating: 90%
Outputs available (kw): 24
Dimensions (mm) height x width x depth: 690 x 390 x 280
For homes with one or two bathrooms, the Greenstar CDi Compact is suitable for small, medium or large homes.
Although it is compact enough to fit inside a kitchen cupboard, this boiler is able to produce output enough for properties with more than one bathroom.
Greenstar Highflow CDi ErP
Brand: Worcester Bosch
Type: Gas Combi
Typical Price: £2,464.00
Rating: 90%
Outputs available (kw): 29.2, 30.6
Dimensions (mm) height x width x depth: 850 x 600 x 600
This floor standing boiler provides industry-leading standards of flow rates for hot water.
If you own a large home with two bathrooms, the Greenstar Highflow CDi is the perfect choice with higher output options available.
Greenstar 8000 Life / Style Combi Boiler (White/black)
Brand: Worcester Bosch
Type: Gas Combi
Typical Price: £1,911.00
Rating: 90%
Outputs available (kw): 30, 35
Dimensions (mm) height x width x depth: 780 x 440 x 365
Available in black or white these combi boilers offer style alongside performance.
With up to 50kw output available the Greenstar 8000 Life Style Combi provides the highest flow rates of any other wall-hung combi.
Able to comfortable provide hot water to two or more bathrooms, the Greenstar Life Style range is perfect for any size home.
Vaillant Combi Boilers
ecoFIT Pure Combi
Brand: Vaillant
Type: Gas Combi
Typical Price: £1,860.00
Rating: 89%
Outputs available (kw): 25, 30, 35
Dimensions (mm) height x width x depth: 700 x 390 x 295
Best for homes where space is a premium, the ecoFIT Pure Combi boiler is perfectly designed to fit inside a kitchen cupboard.
Offering outstanding performance with low energy consumption, this combi boiler offers efficiency and lower fuel bills.
ecoFIT Sustain Combi
Brand: Vaillant
Type: Gas Combi
Typical Price: £1,560.00
Rating: 89%
Outputs available (kw): 25, 30, 35
Dimensions (mm) height x width x depth: 700 x 390 x 295
The ecoFIT sustain range provides comfort alongside a reduced energy footprint. The compact size enables this boiler to fit in all types and size of properties.
Designed for new build and social housing markets, the ecoFIT sustain combi offers a compact cupboard fit with rear flue option.
ecoTEC Plus Combi
Brand: Vaillant
Type: Gas Combi
Typical Price: £2,051.00
Rating: 89%
Outputs available (kw): 25, 32, 35 or 38
Dimensions (mm) height x width x depth: 720 x 440 x 338
The Vaillant ecoTEC Plus Combi offers high performance with control and efficiency.
Using intelligent technology, the ecoTEC Plus knows when more heating power is required and will adjust accordingly.
With efficiency as its goal, the ecoTEC Plus can help reduce your fuel bills.
ecoTEC Pro-Combi Boiler
Brand: Vaillant
Type: Gas Combi
Typical Price: £1,763.00
Rating: 89%
Outputs available (kw): 24, 28, 30
Dimensions (mm) height x width x depth: 720 x 440 x 338
Perfect for small to medium-sized homes, the ecoTEC pro Combi will provide hot water when you need it.
Like all Vaillant models, the ecoTEC pro is Quiet Mark approved so you can be assured of a quiet system.
From vSMART app-based controls to simple analogue timers, you can choose between a range of thermostat controls.
ecoTEC Exclusive Green IQ
Brand: Vaillant
Type: Gas Combi
Typical Price: £2,574.00
Rating: 89%
Outputs available (kw): 35, 43
Dimensions (mm) height x width x depth: 720 x 440 x 474
The ecoTEC Exclusive Green IQ is a premium combination boiler hand-built in the award-winning Vaillant Derbyshire manufacturing plant.
With the Green iQ mark, this combi boiler provides the lowest fuel consumption and running costs due to its supreme energy efficiency.
You can control the thermostat from your smartphone or tablet for additional control using the vSMART system.
ecoTEC Plus Combi LPG
Brand: Vaillant
Type: Gas Combi
Typical Price: £2,051.00
Rating: 89%
Outputs available (kw): 25, 32, 35 or 38
Dimensions (mm) height x width x depth: 720 x 440 x 338
The Vaillant ecoTEC Plus Combi offers high performance with control and efficiency.
Using intelligent technology, the ecoTEC Plus knows when more heating power is required and will adjust accordingly.
With efficiency as its goal, the ecoTEC Plus can help reduce your fuel bills.
Viessmann Combi Boilers
Vitodens 050-W Combi Boiler
Brand: Viessmann
Type: Gas Combi
Typical Price: £748.00
Rating: 88%
Outputs available (kw): 29, 35
Dimensions (mm) height x width x depth: 700 x 400 x 350
With low level operating noise and compact dimensions, this low-cost condensing boiler is perfect for new builds and heating upgrades.
The stainless steel heat exchanger efficiently converts energy into heat, consuming less fuel. This means low CO2 emissions and reduced environmental impact.
Vitodens 100-W Combi Boiler
Brand: Viessmann
Type: Gas Combi
Typical Price: £952.00
Rating: 88%
Outputs available (kw): 35
Dimensions (mm) height x width x depth: 700 x 400 x 350
One of the more popular options for small and well-insulated homes, the Vitodens 100-W Combi is compact, affordable and quiet.
With smart technology, you can optimise your heating and save money on fuel bills.
The now-Radial stainless steel heat exchanger makes this an extremely efficient boiler for use in any living space.
Vitodens 200-W Combi Boiler
Brand: Viessmann
Type: Gas Combi
Typical Price: £1,232.00
Rating: 88%
Outputs available (kw): 26, 30, 35
Dimensions (mm) height x width x depth: 850, 450, 360
This is a quiet operating boiler with easy to use controls and timer options.
The Vitodens 200-W Combi has high-efficiency ratings converting 98% of its fuel into heat.
The ability to access all components easily from the front results in low maintenance costs as no side clearance is required during servicing.
By using the ViCare app, a trained installer can be notified automatically if there is a fault in the system.
Grant Combi Boilers
Vortex Pro: External Combi
Brand: Grant
Type: Oil Combi
Typical Price: £2,575.00
Rating: 85%
Outputs available (kw): 21, 26, 36
Dimensions (mm) height x width x depth: 945 x 685 x 754
The Grant Vortex Pro boasts some of the most impressive energy efficiency ratings for UK boilers.
The large heat exchangers vastly increase hot water performance due to their large surface area and low water content.
Using Riello low NOx burner technology, these boilers meet the low NOx emission targets.
Vortex Pro: Internal Combi
Brand: Grant
Type: Oil Combi
Typical Price: £2,506.00
Rating: 85%
Outputs available (kw): 21, 26, 36
Dimensions (mm) height x width x depth: 860 x 614 x 606 (21, 26kw) / 900 x 614 x 606 (36kw)
The Vortex Pro Internal Combi boiler offers quiet operation and increased hot water performance.
The electronic temperature controls allow you to make use of the condensing mode for adding hot water production while heating.
Fitted with the Riello RDB Lo-NOx burner the Pro Internal Combi offers exceptional energy efficiency and low emissions.
Vortex Pro: Internal Compact
Combi XS
Brand: Grant
Type: Oil Combi
Typical Price: £2,534.00
Rating: 85%
Outputs available (kw): 26
Dimensions (mm) height x width x depth: 857 x 515 x 606
The Vortex Pro Internal Compact Combi is only 515mm wide. This makes it smaller than most oil combis.
However, you will need to find extra space nearby to fit the 24-litre expansion vessel.
This is a popular boiler to be used as a replacement boiler for older less efficient appliances.
The compact Vortex Pro Combi XS makes it perfect for upgrading boilers with small spaces available.
Vortex Blue Combi Internal
Brand: Grant
Type: Oil Combi
Typical Price: £2,883.00
Rating: 85%
Outputs available (kw): 21, 26, 36
Dimensions (mm) height x width x depth: 860 x 614 x 609 (21, 26kw) / 900 x 614 x 609 (36kw)
Grant VortexBlue Internal Combi uses the latest low NOx Riello oil burner technology.
As a result, it meets low NOx emissions targets and is future-proofed for lower NOx emissions targets.
The large heat exchangers and low water content offer improved hot water performance.
Vortex Blue External Combi External
Brand: Grant
Type: Oil Combi
Typical Price: £2,949.00
Rating: 85%
Outputs available (kw): 21, 26, 36
Dimensions (mm) height x width x depth: 945 x 658 x 966
Grant VortexBlue External Combi takes advantage of the latest low NOx Riello oil burner technology.
As a result, it meets low NOx emissions targets and is future-proofed for any future lower NOx emissions targets.
The large heat exchangers and low water content offer improved hot water performance.
Are you ready to buy a new combi boiler?
We hope that the information above will help you choose the best combi boiler for your home.
If you are ready to buy your new boiler, we recommend using Boxt fixed price installation service.
Boxt offer an easy to use assessment of your home and will recommend the best combi boilers available to you.
Boxt will provide a complete supply and installation service at the best price available.